249
TrrE: AT,i;.4E O F THE: EAST AFHICAN LAKES
Scierrtific results of the Camhridgo Espcdition t o the East Afric:tn Lakcs,
1930-1.-7.
The Algae.* By FLORENCE
R r c q M.A., P.L.S.
(With 4 Text-figures)
[Read 2 February 19331
As I had recently examined the Phytoplankton collected by Miss P. Jenkiii
from the smaller lakes (R’aivasha, Nakuru, Elmentcita, and Baringo) of tho
Kenya (Eastern) Rift Valley I was glad t o have the opportunity of examining
the Phytoplankton collected by the Cambridge Expedition to t,ho Lakcs of
Kenya and Uganda, and of comparing and contrasting the two collcctions.
Dr. Worthingt.on first submitted t.0 me thirty tubes of plankton, and
later sent mc some additional tiibcs (including il few from Lake Saivasha)
containing ‘ water weeds ’ with attached algal growth ; these later snniplcs
proved very useful, as they contained in abundance some of the dgac which
werc bnt scantily represented in the plankton.
The chief centro of interest was tho collection from Lake Rudolf in the
descrt region of Sorthern Kenya (bordering on the Sudan and AbyssiniZL) ; this
was the last of the great African lakes t o be discovered (18%)) and the Inrgc
island in the Lake, called Central Island, had ncver been visited until 1931,
when the Cambridge Expcdition went thcrc. The algae of this lake have not
previously been submitted to cxamination, though the algae of t.lw otlicr
large lakes of East and Centrnl Africa h r e been fully irivestigatetl ils thc
following references serve to indicate :Lake Nyasa.-Schmidle, W. (1902) (including Victoria Syanzn) : Miiller, 0.
(1903-10) ; G. S. West (1907).
Lake Tanganyika.-West, G . S. (1907) (this also includes plankton from
Xyasa and Victoria Nyanza).
Victoria Nyanza.--Schmidle, W. (1902) : Ostenfeld, C. H. (1908) : Woloszynska, J. (1914).
Lake Albert.-West, G . S. (1909).
There is also an account by R. and G. S. West of some Algae from Central
Africa col1ect.d by Dr. J. W. Oregory during a.n expedition to Mount Konya
in 1893 (Journ. Bot. xsxiv, pp. 377-84).
*
From the Hotanical Drpart rnent, East London C~ollogc, University o f London.
intlohtetl t o tho Carnegie Corporatioil for fhc Atl\anrrmerit of Iirsearch for n grant,
mndo through tlir Hesenrch Grant l k m d of 1 1 1 ~P n i o n of South Africa, which 11as ttitlrtl
iiio in this work.
T
turi
LINN. J0URN.-ZOOLOGY,
VOL. X X X V l I I
18
The Diatoms collected by the Rhodcnia-Congo Expedition in 1911-12 were
described by S. Rrlandzlson in 1828 (Svensk Rotan. Tids. xxii).
In fact, so much work has been done on these African lakes that t h r t ?
is probably not much new left to discover, and the presont paper, apitrt, from
minor points, contains but little of interest.
Osterifeld (1908) remarks thut the phytoplankton of Victoria Xyanarr ilnd
Lake Xyusa bear a great resemblimce t o each other, the dominant species
i n both laken being the sttme. The former lake was richer in species, this
being mainly due to tho occurrence of many hsmicis.
I n tlte following list a note is ridded uftnr each specins if it has previously
beun recorded from the above-mentioned lakes-it will be seen how many
Algae art) common t o two or mom of them.
In commenting on the phytoplankton of the large African lakes G. S. Wost
(ln(J7) dritws attention to the absence of many gunerit which irre dominant
features of the European hike-plankton n t certain seasons of the yew, referring
Ixtrticularly t o the genera Dinobrym, Aderionella, l’abellaria, Rhizowbnia,
and Cwlospherium. Of these, Coclosphaeriurn was found by OHtenfeld (1!)08)
in Victoria Nyanm, and it occurs in the prcsent cdlwtion, and Asterionslln
iLlHo occurs in the prenent collection, while Dinotrrgon and 7’abrllatGuhtrve been
found in the Trannvaal. (See Rich, F.,1932.)
Dr. Worthington’s collection was made in every month of tho. year cxcept,
October : prttvious collections of pl~~toplitnkton
from the Great L1Lkt.s hncl
been mude in the months of Februtiry (l!K)R), April (1905), October ( 1 H92),
and Kovembcr (1904).
Of the lakes now under considerrrtion the following ctlgno mil?. bo looked
upon as distinctive features :Of Lake Rudolf, Hwmidiibm, Rubtile :
Of Crater Lake A on Central Islund, Rhoplodin qibberula ;
Of (:rater Lakes I3 and C on Central Tsland, Arthrospira p1nten.si.s :
Of Lake Edward, Surirella biseriota and Microcystis jlos-aqucw ;
Of Lake George, Microcystis $os-agztae und Sgmdra spp. :
Of Lake Uunyoni, Rhopahlin, sevcritl spwitts :
Of Lake ?u‘akavali, Microcyst is ,flos-quae rind fifrhsira qraniilala, and
vrtr. anyustissima ; and
Of Lake Kwhira, Microcystis jlos-aquae.
The Desmidiitceac were fourid t o be poorly reproaented in the plankton
of‘ Liikes Tunganyika and Xyasa, but they were said to play a conspicuous
rijlt! in the plankton of Victoria Nyanzu. The only lake of this region examintd
by me in which nesmids were other t h m very ram was Lake Niiivaslia.
Ntatirastrum lim7Leticitni Schmidle, a npecics of similar type to S. 0phiw-a
Lund., which is generally distributed in mitny lrikes in the wostern urtwi of
the 13ritish Isles, was stuted to be the most abiindant 1)esmicl in thc plankton
of Victoria Nyanzn, but I have not come ucross it at, all. Thc few Dnsniitls
now found indicate that Homewhere in these lakes they may bt! more abundant.
Soteworthy among t h e Diatoms ( RiLcill:trisles) present were the Rhopalodins,
which occurred in Lakes Edwtird, Bunyoni, itnd Rudolph. The species with
asymmetric frirstules seem t o be confined t o the continent of Africa, and
hiive hitherto been recorded only from Lltkc Nyasa and its neighbourhood.
The thick, dichotomoiisly 1,ranc:hed stalks of R. vermicularis and 3.hirrcdinif’ortnis described by Miiller (1!)05, 1). 161) are figured for the first time in the
I)resent paper. A new form of R . zerrnicularis is described. The Surirellaceae were said to be well represorited in the plankton of Victoria Syanza,
Tmganyika, and S y a s ; ~; from Lake Naivasha. a form of fhirirellu linearis
was figured in 1V32 (Rich, F.,fig. 3, D.E.), and from Lake Edward various
forms of a large and handsome Sicrirella have now bcen obtained-these forms
can all be ascribed to S.biseriatu or its var. subconstricta. Two other Surirelliis
were observed in Lake Rudolf, one of them, i~ now variety of S . biscriata,
WLLSfairly common in the sarnplt? taken from open water one mile from the
end of Ferguson Spit, but was not observed elsewhere: the other was very
r:iro md was not determined. The species of Surirella now found seem to
be ditrerent from those previously recorded for tho great lakes. A new form
of Asterionella gracilliina is figured.
Flagellates (Eugleninae) were present, but in very small quantity only, in
Lakes Nakavali and Saiviisha. Ceratiwn hirundinellu, a Dinoflagellate
tlomioant in the plankton of t,cmpcrate Enrope, and which was present,
though of sm;tll importance, in tho collec!tions from Lakes Victoria and
Nyasa, wiis not found a t ;dl in tho collection now under considoration.
The Myxophyceae were well represented. By far the commonest alga
found was Microcystis ,pos-aqwe, which, if we include the allied M . aerugimm,
seems t o be very widely and :ibiindnntly distributed in Africa.. The genus
-4phanocapsa is ;ilso very common. Three spoc:ies of Anabaenopsis worc
observcd, two of which appear i n previous descriptions to have been confnscd
with one another. Two spirally coiled T,yngbytis have been figured, a s , again,
thcw seems to have hwn some little confusion about them. Some I3lue
(keen Alg;~ethat, owing t o the stat(?of prwcrvation, could not be fully described
hi~vubcen figured, in tlic hope that further collections may throw more light
iipon thern.
Several of the ;~lgnefound have bnen t?xclrrdrd from the following iIcco1lnt
owing to tho clificulty of iclontifying them with m y degree of certainty : such
plants were mostly in a fragmentary condition and some were biully prc?served:
itmongst them were species of Nostor:from Lakes Rntlolf a n d Nitivasha, imd of
Valothriz from Lakes Ceorgc, R,iidolf, and Xakavali.
Filuments of Ordogonium, Spirogyyra, and Moiageotia occurred, Imt never
in the reprodrictive state, and the spccies, therefore, could not be satisfactorily
tlet.crmined.
Spira.1 coiling, i i featnre of many different species and genera of the phyto~ h ~ k t . oinnilliistr;it,cvl
,
Irnrc? by the oeciirreiicc of I;!/n&p circumreta, L. Lagrrs , two species
hcitnii, A rthrospira plri.trnsis. tlircc spwiw of ~ I n a k ~ r n o p s i ant1
of Spir it lina.
18*
Enzrmeration of the samples nnd their m,ost commmtly contained specie#.
Wliere not otherwise stated the simples :Lrn planktonic, obtaincd with
fine mosh silk pliinkton net, (75 meshes t o the ccntirnt?tlc). The numbers
of' the s:tmples reter to the expedition's station list (Wortliington, 1Y32).
The commonest alga, a s a rule, is pliwed first, tho others arc in no definito
order.
iL
Lake Naiimha.
(-4s the phytoplankton from this lake has boen examined ftt.irly recently,
(see Rich, F., 1932 a ) , only snch samples arc: refcrrcd to Iiero as contained
sI)ecies n o t previously recorded for TAiLkeNitivasha.)
18. November 1'330. Mdosira amhigua, Lyngbya circumcreta, Hotryococczts
protuberam.
30. February 1031. 10-5
m. Melosim ambigzia, 31. yran,uldu v:w.
nnpistissima, Anabaenopsis tanganyikae. Lynybya circitmcrrta, Coalosphafiriii?n
n i n ~tissincli,ni
i
, K irchneriella obesa , A piumocapsa elacfiista, 11. del icat issipi I a,
Aphanothece sp., Rotryococeus protuberans, Scenedesmus obliquws, Stau,rastr.irni
Dickiei.
31 (2). February 1931. Rotr?pcoccus prohberans, Mozigeotia sp., Gi~nrpkosphueria aponim, Phorndi.tLnt ealderianicm, ( 2 ) Anabucna sp., Staiwastritm
Dickiei, Pediastrum tetras.
30 (2). March 1931. Nosloc HIT'.
, Spirogyra sp., Gloeocystis gigay, Cnrciymin
rectangularis, Nephrocytiunt lunntiim, Gloeotrichia ndan.s, Ankistrodesni.ics
frrlcahis, Phacus pleuronecteu, Stuzirastru.rn,Dickiei var. circulare..
43 (2). May 1'331. Oedqcrni?m sp., (;i7elosp?merium Kiitzinyianum.
Luke Baringo.
106 A (1). Dee. 1930.
dlicrocystis jlos-aquae, Aphanocnpsa Grevillei,
Melosira yraniilata var. angvstissima, Nitzschia microcephala, Phorwidiunt
'~t~ucicola,
Y . autiLmmdu.
117 (2). Jan. 1931. Microcystis, Aphanocapsa, n.nd Mclosira as above.
121 (2). Jan. 1931. Microcystis and lCfrlosirn as above.
Lake Rudolph.
211 13 (1). Dee. 1930. Artiiroapira Ylatenais and f . minor, HirrniirtiiinL
subtile. This sainple was from nn cncloseci alkdine pool on Perguson simdspit ; sen also samples 257 and 257 ( a ) .
216 (2). Jan. 1931. Hormidiwn subtile, d ~ i c r o c y s l i s ~ o ~ a
s -few
~ u diatoms.
~,
220 (5). Jan. 1931. Incrustation on wiLtor-weeds. Lyngbya lutea, Nostoc sp.,
C'dothriz sp. Diatoms.
221 (1). Jan. 1931. Shore-weds in lcc of Fc:rgiison Spit. lihopalotlia
gracilis,
234 (2). March 1931. Horinidiuin subtile.
248. March 1931. IKortnidiun~subtile, I'hortt~idium niolle, Cyclotella Menegi~iniana.
250. Xarch 1931. HornL idiuin subtile , Uotrywoccus' Hrauni i , I'lwrmidi utn
7twlle.
257. March 1!131. Arthrosyiru Platemis.
guson Spit, see also 21 I .
Enclosed alkaline pool on Fer-
2,57 ( u ) . hlirrch 1!131. Alkaline pool ;is ;hove. Anabaenopsis Anioldii,
A rthrospira I'latensis, Kirchnesiella lunaris, Crucige7iia qu&ah.
25s (2). March 1'331. Horttiidium subtile, Botryococcus Hraunii,
Diatoms.
;t
few
261 (2). March 1031. Similar to last.
266 (3). April 1'331. From stomach offish (Clarim). f'horrtaidiuwr autt~tir.nule
and Diatoms (Ootnphocytnbella Urunzi, Rhopalodiu yracilis, K. hirudiniformis,
G'rmiphonen~asp.).
269. April 1'331. Crater Lake B on Central Island. Arthrospira platensis.
271 (2). April 1Y31. Crater Lake A. A good deal of organic dCbris,
Ilwmidiuttb subtile, Rhopalodia gibberula, Skrire1l.a Diseriata var. lanceolata,
Calothrii sp., Ritdaria Bimolettiana, Lynybya luteu.
273 (2). April 1931. Crater Lake C. Arthrospira platensis.
287 (2). April 1931. Water-woeds on west shore covered with a t.liick
incrustation of diatortis. Khopalodia hirzidiniformis, H. w.ntriw,sa, R. yrilcilis,
K.gibberula var. riipestris forma crassa,Cy/nibclla grossestriata var. obtusiuscula,
L!. helwt ica, Cmnphoc?jmbella Hrrini, (hnphonerna intrimlum, Cpclolella M c n e ghiniam, Xauicula pupula, N . sphaerophoru V~LI'. rostrufa, N . cryptocephala,
N itzsch ia hungar ica.
Kazinga Channel, b'gandu.
510. May 1%j1, Microcystis jios-aqiiac, Aphanocapsu Grwillei.
527 ( I ) , June 1931. hl.jlos-aquae,I'ediastrum simrplez var. radians, dfdosiru
anibigua, Sitzschia niicrocephala.
Lake Edward.
528. June 1931. Microcystis ,flos.aquae, f'edimtvum simpkz var. radiaiw,
Staurastrum sp.
530 ( 1 ) . ,June lY31. Xicrocystis 30s-aquae, I'edhtrum simplex var'. radiam,
P. duplex vw. reticulatum, Dictyosp?merium pulchellum, Tetraedron mininium
formiL, Staurastribm pardoxurn, Botryococcus Braunii, Surirella biseriata
and two viws., Anabaenopsis tanyanyikae, Chroococcus minutus, Lyngbya
Lagerheinvii.
6-U (3). ,June 1!Y31. Incrustatiori on wutor-weeds. Rhopulvclia hiricdi?iiformis, R . yracilis, C;'o,&ocynilrella Uruni, C'ymbclla sp., L!/tLgbga sl).,
Anabaesla sp., Microchaeta sp.
562 (2). June 1931. .IIicroc?/stis jlos-ciyrtw, Surirellti O~iserida V M .
yarallela.
d
j
-
571 (1). J illy 1931. iVicroc!/stis jlos-uqua(,, 1'edimtr.uttt dirplcs vur. rcticulat tim, Aphanocapsn Crc.r:iElei, Stuitrastruwi paradoxurn, L p g b y a tip.
571 ( 7 ) July 1931. ,Vicrocy
jlos-aquae , S.urirr2la biscriata
cotaslricta, L'ycloklla Mcncyhiniana, Slauraslruni sp. , L?/iiybyci sp.
. s111)-
vii I'
Kuianda Lagoon.
I,. C. Reiidlc collection, July 1'331. dtuzhwtwpsis circularis, 4 . I n i r y a n yiktcc, Aphanolht!w sp., rYpiruliii(L stiblilissirtiu, C1osttiurL'~uitt w.ranyitlnri~ f .
ni i n i t t i u, Lynybya W r r h ci,trt.i i, lthopulorlia yriccilis, C 'oclosphacri.u,ttt,(:oc.lxi,
2Meris?nopediatc~uuissirt~u,
Lake Gemp?.
ti03 (2). July 1931. Microcystis ,/los-quw, Pcdiuslrii?ti sitnplez viir. rudiatis,
r l p h a m p s a Gredlei.
617 (6). July 1931. Sijiroggra q).,Mougeotia sp., Odoyonium sp., (:'~(Jsttriiirrt. P i t z i n y i i , Nywrlra ulna vtw. suhaepalis, 8. acus var. anywtissitia.
Asterionella sp., Nitzschia ,trricroccyhala, Hhopalodia yibita, C'a1othri.x ~ 1 ,) .
Nodularia spumiyena, Oscilldoria ten,uis, Analiclenu 2 spp., h$irulinu mujor,
Micrwhaete sp.
.
ti23 (2). ,July 1931. Microcystis jlos-ayuue, riyhanocupsa ~ 1 ) .
Lake Bunyoni.
707. AllgllNt 1931. (heyid1 brown mass
Lyngbya liitea forma.
011
woodcn piles idoIg shore.
707 A (3). August 1931. Growth on water-weeds on show. Uistomti
together with filaments of ASpirogyra and Oedogoni,urn. (Rhopalodia hirudinifvrmis., R. vermicularis fornin recta, h!. gihbu, and others).
729 (2). August 1931. Stomach-contents of fish (Tilapia). Synedra mus,
Is. .uhm, Naoiculrs vulpiw (?), G'mnphonrma brachyncuru, C. intracatum, Gymbella
venhicosu (?), Epithemia zebra, h'hopalodia gibba, R. ceruaicularis forma recta,
Nitzschia ccntmunis var. perpusilla.
Lake Nakavali.
812 (13). August 1931. From weedy shore. Much organic: dbbris. Scennrdesmus prot uberans, Cryptonw?tas w h ,Cosmariurn hwtiile forma, Achnanthcs
lanceolda, Melosira granulda and var. mgustiesima, L?jq,hyr~ circmicretn,
illicrochaete sp., Calothria: sp., ? Lynybya sp.
814 (3). Supt. 1931. Microcystis jlos-aquae, Uictyosphaeriutn pulchelluin,
h'cenedeumus prduberaias, Scenedetmus sp., l'ediwtrum duplex var. reticulalurn,
Coeh-trum cainbricuin var. rugosum, ('losterium Kutziwjii, Ankistrodesmus
falcatw, Stuurastrum sp., Melosira granulata and var. anyustissiina, A ~ ~ T L v capsa elachista var. planctonica, A . G'revillei, Mcrismopedica tenuissima, Coelosphaeriutn minutissiinum, Lyngbya circurncrcta, l'raciie1oirLonu-s hispida form;L,
Phacus longimudu var. torta, E'w~lcrul wus, Gymnodinium sp., I-'hvrmidium
atubiguum.
L a k e Kachira.
$24 (2). St:pt. 1931. Microcystis jlos-aqua(!, X e k s i r a yranulata, Lyujbya hp.
Lake Kijanebalola.
833 (2). Scpt. 1'331.
Microcystis jlos-aquae.
Systetnotic cnuriwration of thc sp(;cies obscruecl.*
(A roferunce idtor tlit, specific: name is given, oscopt in ooinmonly ruoordctl
species, wliun tliere is in osiutenco B figure ruprosonting the alga observed.)
Class I. ISOKONTAIC.
GLoEocywrrs MGAS (Kutz.) Lagerii. West & Fritsch, 1027, tig. 18, ( i .
Lake Naivashu, from weedy shore, 3!#. Very rare.
Recordd from Tanganyika and Victoria Xyanzu.
PEDIASTRUM
SIMPLEX (Meyen) Lemmortn. var. KAI)[ASS h u e r m .
Kazingi~Channel, 527 ; Lake Edward, 528, 530.
Forms of 1'. simplex abundant in Lake Kyastt.
PEDLlSTHUM DUPLEX Meyen var. RETICULATL'M LilgOlh. Paschur, 1915,
v, fig. 57, h.
Lake Edward, 630, 571 ; Lake Nakavali, 814.
Recorded from Victoria Xyanza.
PEDIASTRUM
TETRAS (Ehrenb.) Ralfs.
Lake Naivasha, 31.
Hecorded for Nyasa, Ttariganyika, and Victoria Xyanza.
LUBATUM West.
XEPHROCYTIUM
Lake Naivasha, 39.
Rscorded for Tanganyike.
TETBAEDRON
MINIMCM (A. Br. ) Hansg. forma APICULATUM Reinsuli.
Lake Fdward, 530.
The type recorded for Tanganyika, Albort Nyanza, and Lake Saivasha.
'
* Tho systoin of clttsaifictltion followed ia thtlt of F V d , C:. S.,and lhiituch, F. E., in
British I'rashwater Algae.' etc. (Cambridge, 1927).
Ridfti ( - f&&phdiU'ffL
f U k d U S Cord&).
Lakc: Kaivasha, 39 ; Lake h'akavsli, 814.
Recorded for Nyasa, Tangmyika, a i d Victoria Syeriza.
L~~KKIS'I'IIOUESMCS
FATLL4TUS (C'OI'dtb)
KLILCIINEI~IELL.~
LUNAHIS (Kirchn.) l\liibius.
Alkalirie pool, 257.
Cells 8-10 p across.
Kccorded for Xyi~saeiid Lakc KaiviLslie.
KTRCHNERIELLA
OBESA (West) Schmidt,. Ueflandro, lY!4, p. 670, fig. 1 ( 7 ) .
Lake Kaivasha, 30 (5-10 mctrcs).
The appcxtriuic:tt is that of thick discs irioistxl to a third or half t.hc witltli
ot' the cell, as described by G . M. Smith, 1'320, in thc ' Phytopleiikton of tho
Inland LtLkos of Wiscomiri,' p. 142.
Recorded for Albert Nyanza, Tanganyike, and Victoria Nyun~ii.
~)ICTYOSPHAENILX PCLCIIEILURI Wood.
Ltikc Edward, 530 ; T,;Lkt! Nakiivdi, 81.1.
Rocorded for Nyasa, Tanganyika, Victoria. S yaiizib, and Xuivasliit.
CRLTI(;ESIA QLADI~ATAMorren.
Alkalino pool, 257 (a),rcither common.
Ctrlln itbout 4 p.
CRUCI(;ESIA m c i x N G u L A i t 1 s (A. Ur.) Gay ( = SluuroyeiLiu rechnguluris
A. Br.).
Lake Naivasha, 39, very rare.
Kccorded for the neighbourhood of NYiLS;L.
SCENEDESMGS AltCUATUS Lommorm. vw. PLATYUlSCA ( i . A[. Smith, 1'320,
pl. xxxix, fig. 3.
Lake Nakavali, 814.
ltucordud its S. bijugatus (Turp.) Kutz. forma arcziatu (Lemmcrm.) W. &
G . S. West for Tanganyika.
SCENEDESMUS
OBLIQTJIJS (Turp.) Kiitz.
Lilkc Kitiv;tdia, 30 (all depths), in Uactylococcus stage.
Recorded for Nyasa, Albert, TanganyiktL, end Lakc Nnivaslia.
S c e s ~ u s s ~OPOT,TENSTS
m
P. Richter ver.
CARISATUS
Lemmerm.
Lake Nakavali, 814.
8CESEDESbIUS PI<OTCDERASS Fritsch
& Rich. 1929, fig. 6 , R.
Lake Kinkavali, 812, 814.
QUauaIcauua(Turp.) Ur6b. vaz. DICACDATUS Hensg.
Lake Kakavdi, 814.
The type recorded for Kyasa, Tanganyika, Victoria. Nyanza, and Lake
Naivasha.
SCEXEDESMUS
257
COELASTRUM
CAMBRICUX Arch.
Lake Maivasha, 3'3, very rare.
Recorded for Kyitsi~,T a n g a n y h , and VictoritL Syanza.
Var. HCGOSUN Rich in Trans. Roy. Soc. S. Africa, 1932, xx, fig. 3, J.
Lake Nakavali, 814.
First observed in the Transvaal.
HOEXIDIUM
SUBTILE (Kiitz.) Hewing ( = ,!!tichococcua sublilis Klurcker).
Lake Rudolf, 211 €3, 316, 234, 348, 350, 258, 261, 271 ; Lako Nakibvdi, 814,
very rare.
Kot found in .samples from the t J t h O r lakes. -4 chlrratoristie feutiire of
Luke Rudolf.
Kecordcd for the Mwangdan Rivor, Centrd Africa, iis Horrniscia subtilis
(Kiitz.) DC:Toni var. ,mriubilis (Kiitz.)Kirclin., and for Lako Xaivasliu.
Y N I C ~ W T ~ I ASI~RICTISSIMCX
MN~ON
Rabcnh.
Lake NitiViLShil, 39, W O ~ shore.
Y
A s only a mere fragment was obsorved the deturdriatioii is not o u r t i h
OEDOUONIUM
sp. Vegetative cells 6-7 p wide.
Sterile matcriiil only.
Lake h n y o n i , 707 A.
O~WOGONIUM
sp. Vegotative cells, 14-17 p wide. Sterile matorid only.
Lake Naivashii, 3!j, 43 ; Lake Baringo, 106 A ; Lako Bunyoni, 707 A ;
Lake Kachira (among Bladder-wort).
SPIROGYILA
sp. Width of filament 16 p. Sterile mat.erial only.
Lake (+eorge,617.
kji~iitou~iea
sp. WitltJi of filainont 32 p. Sterile material only.
L&o Kaivasliu, 39 ; Lake Edward (S. cnd ; wuocls) ; Lakc Uunyoiii,
707 A.
MouoEoun 2 qq). Stcrile rniitcrial only.
Liko Naivasha, 31, 39 ; Lake George, 617.
CLOSTERIUJI
K ~ T Z I S G Br6b.
II
Lake George, 617 ; Lake Nakavali, 814, very rim.
Necorded for Xyasa and Lake Saivitshs.
COSMARIUM
QRANATUM Br6b. W. C(t G. S. West, 1904-12, ii (1905), 111. Ixiii,
fig. 3.
Lake Kakavali, 812, very rare.
Recorded for Nyeva and Lake Xaivasha.
Cos&miUx I ~ U M I L E( ( h y ) Yordst., forma.
Lake Nakavali, 812. Only one inclividual observed.
Apex undulate ; no granules seen.
Long. 16 p ; let. 14 p.
COSMARTUM S E X A S G U L A R E h l l d forma MINIMA Nordst. w. & G. 8. Wed,
1!108, pl. Ixxii, fig. 5 .
ibiandtb Ltigoon, h k o Edward, riLthor common.
Long 14 p : lat. 12-13 p ; isthm. 3 p.
ltccordocl from Ccntriil Africa.
STAURASTRUM
DICKIEI
Ralfs.
Lake Kaivasha, 30.
Tri ~ h i mudl
~ p ~moro likc the pl)linlitd figures o f var. ttuzxittLuitL W. & C:. S.
West, but the diniensionx agree with those of the typo.
Var. CIHCL‘LAIIE ‘l‘urncr. Wcst & Cnrtcr, 1!)23,pl. cxxix, fig. 16.
Lake Naivdia, 39.
P A R A I) OX U M Meyen.
Lako E d w d , 530 and 57 1.
1’ri-radi;rtcr. big. cell. 26-28 p ; lat . cum proc. 50 p ; iuthm. 5 p.
ltecordtd for Victoria Kyanzu.
STAU RASTRU M
(:laus 11. HETEROKONTAE.
Uu-rityucoccrrs BIIAIJNII
Kutz.
Lakc Rudolf, 250, 258, 261 ; Lake Edward, 530.
liecorded for Nyasa, Tangenyika, VictoriiL Nyaii~a.
m’.
&
J d i o Nitivaslia, 18, 30 (all depths).
~ O ’ Y S Y o C o C C I’ltOTI’RERASS
~S
(;.
s, West.
According to Paschcr (‘ Susswamerflora,’ xi, 1). W!) B. prolubcrms iiitty Lc
only LL sttlgc in developmcnt of the preceding HpcieR.
I’rcvioiisly recorded for Lakc Xaiwshu.
Class 1V. UACILLAHIALES.
Croup A.
CENTBICAP.
0. Mull.
Lake Nuivauhn, 18, 30.
Recorded for Piyasa and Victoriii Nyanzu.
~ ~ Y L O S I H AMBIOUA
A
MELOYIRAGRANULATA (Ehronb.) Ralftj. 0.Mullor, 1904, Tab. iii, fig. ti.
Lake Nttkuvali, 812, 814 ; L&e Kachira, 824.
Width of cells from 12 to 25 p.
liecorded from Nyasa, Victoria, and Albert Nyanza.
Var. ANQUYTIYYIMA 0. Mull.
Lake Naivauha, 30 : Lake Baringo, 106 A, 121 ; Lake Nttkavali, 814.
Width of cells .W p.
Recorded from Victoria Nyanza and Luke Baringo.
CPCLOTELIA
MESEGHIKIAS A Kiitz.
Lake Itridolf, 248, 287 : Lake Edward, 571.
STEIWANOUISCI,S
ASTROEA ( EJirennb.) (:run.
Lake ltridolf. 287. \'c?ry rare, and idontific:iitioii is a little doubtful.
Itecorcled for the plankton of Nyasa and Victoria Nyanza.
Group 13. P'ENNATAIS.
SYNEUI~A
ACUS Kiitz.
Lake George, 017 : Lake Bunyoni, 729.
Cells with a slight constriction in the middle as found in (:riqiialantl Wost
(l'ritwh & Iticli, Trans. Roy. Soc. 8 . Africa, 1929, sviii, p. 95).
Var. ANCII:STISSIMA Grunow.
Lake George, 617.
SY N E: I ) ILA I:LN A (Xitzsdi.) I4irenb.
viir. s~ ~ B A E Q C A L IGrunow.
S
Lake (horgc, 617 : Lake Hunyoni, 72'3.
Recorded for Lake Kaivasha.
(Hantzsch) Heiberg, forma iiov. (Text-fig. 2, C.)
Lakc Georgo, 617. Kot enough present to admit of a preparation, suitable
for detailed examination, to be made.
Ditfert a typo amplitudine latiore solum.
Length 120 p ; width 5 p.
Two freshwater species only of Asteviondla are known : tho present form
approaches one of tht:sr: ( A . grixillirna) in hibViIlg t h e enlargements at both ends
of the same size, but it is broder, the shank measuring about 5 IL ; ~ i i dthe!
terminal knob X p .
;1storionalh is a regular and abundant constituent of thc planktoil (Jf
European lakes, but it has not hitherto been recorded in plankton from Africa.
One colony W ~ . Lobserved
R
in a samplc from Natal (Fritsch & Rich, 1924, 1). 380)
on scum on submerged stind.
;\STEH.iOSELLA GHACILTJMA
AClI1;ASTHES ( MICROKEIS) ~ A S O L E T T I A N A Kiitz. Meister, Die Kieselalgen
der Schweiz, 1!112, pl. siii, fig. 4.
Lake Rudolf, 216 ; Epiphytic on Surirellu biac?riutrs vim. lanceohta.
Long. 14 p : lat. 6 p .
ACHNANTHES(ACHNAKTHIDIUM)
LASCEOLATA 13ri.b.
La.ke Nakavali, 812.
NAVICI:LA
CRYPTOCEPIIALA Kutz.
Lake Rudolf, 287.
Long. 26-32 p ; lat. 6-7 p. Thc middle striae shortor than the others.
SAVICULA
PUPULA Kiitz. 0. Miiller, 1'310, p. 82, Tab. i.
Lake Rudolf, 287.
The few individuals found agreed with Miiller's dimensions, save that they
were a little wider, 12-13 p (Miilkr gives 6.5 to 10.5 p aa the width).
Recorded for Lake Tanganyika.
? KAVICLLA
SALINARUM Grun.
T&c Itudolf, 216.
Long. 24 p ; Iat. !f p. Stritto in the middle alternately long and short..
x~l\~lCtiLA
( 1 ~ S O M U E U f i N l S ) SPHAEROPIIORA
(KcltZ.) PfitZel'
VBP.
KOSTRATA
Miiller, 189!f, Tab. xii, fig. 3.
Lakc Rudolf, 287.
Long. 42 p - t h t is, shorter than tho Egyptiiiri variety described by Miillcr.
The typc recorded for Lakes Ntdvasha illid Nakuru.
! NAVICULA VULl'INA KUtL.
LtLkt! ltudolf, 287 ; Ltike Uunyoni, 729.
~ ~ n M I ' I t o S E M URACHYSEURA
A
0.:'dull.
Lake Brinyoni, 729.
The striae art: shortc!r thiln those in tliu spcimens from Natal figured by
Frjtscli i d Rich, op. cit. 1924, fig. 30, D.E.
Long. 18-31 p : I i t t . 4-6 p ; striae in 1I) p circa 10.
Itocorded from Xyasa.
ISTHICATU,M Kiitz. Fritscli & Kich, l!J29, fig, 6, 11.
Lako Rudolf, 287 ; and Tlake Bunyoni, 729.
Rocorded for Lakcs Saivasha and Kyasa.
(:OMPHONEMA
(:OMPHONEMA
spp.
Lakc Rudolf, 2Ni.
( ~ M P H O C Y M R E L L AUrtusl (tc'rickc)0. Mull. ('l'exb-fig.1, G I . )
Lake Rudolf, 266, 2x7 ; Lake Edward, 542.
Found on the western sliorc of Libkc Rudolf attidlcd by sleivlor stalks
to wittt:r-wtads. Thc existence of RtiLlkH has not before Imuri noted, t81iorigh
Like Uunyoni, 707 A,
i L d
I'roiu thc close resernb1;tiicc of G'omphocymbella to the goriera Cotti,phonenla
itntl C y t t t h e l h it must have been inferred ; both long and short dichotomously
branched stalks wero obscrvcd and are nhown in fig. 1, G & H. The midmost of the dorsal striae shows the characteristic ntigmit composed of rnorc
than one punctum : tho adjacent stria (on one or both Rides) is shorter. This
spc&s is very variable i n shitpo, zi fact which is indicated by Miillcr's two
figures (1905, Tab. i, figs. 2 & 3). An occasional abnormal form was observecl
in wmple 287, see test-fig. 1, I.
Long. 38-44 p ; lat. 10-12.5 p.
Prcviously recordd for the neighboudiood of Laku Nyasa.
CYlIIjELLA URUSSESTRIATA 0.Mull. var. 0B'I'lJSTl:SCIJLA 0. 1MUll. (1wH,G,'ral). i,
fig. 13, iInd Erlirndsson, 1928, xxii, fig. 1 , f ) . (The numbers 12 and 13 on
Niiller's figures should bc reversed.)
Lake Rudolf, 287.
Long. 25-31 p ; h t . 8-5-10.5 p.
Rucordcd for Uganda and Lakcs Nywib, Tanganyika, and Zu'aivasha.
261
TIIE EAST .\BHICAS LAKES : THE ALGAE
CYMBELLAHELVETICA Kiitz. W. Smith, 1866, ii, pl. ii, fig. 24 n
L:Lko Ttl1dolf, 287.
Long. W-fi7 p ; I i L t . 12.5 p. Stria(: in 1 0 p 12.
TEXT-FIG.
1.
H
i
i'F
1
I
-4-C. Httopalodia vermicularis 0.Miill. forinn n o r . recta.
1)-F. Rl1opnlorlMl hiT?ctli?rIfoll,l1s 0. Mull.
(:-I. G'ompt~ocymbellaBricni (Pric.k(.) 0. M i i l l . I, abnormal form.
A, I), x I 0 0 ; 13. C', 15, F', x 4 0 0 ; G l , x 750.
? CYMRELLA
VENTRICOSA Kiitz.
Lake Hunyoni, 729.
J’rohtthly this species. but no ~mtc:ili~p;e-t~~
hes were o b w r v d .
Pmvinusly recordd for Titnganyikn.
ZERRA Ehrenb. var. PORCELLIY (:run.
Litkc Ritnyimi, 72!).
Prciviously recorclcd from Lake Naivcbshs.
&:PITIIEMIA
Rich, 1932, fig. 3, A, R .
ItliOPALODTA GIBHA (Ehl’Onb.) 0 . Miill.
T,ako (horge, 617 : Lake Ritnyoni, 729.
Previously rccortlwl for Lakes Tanpngika and K imii.
(Ehrenb.) 0. Miill.
T,nko Rudolf, crtttcr lake A on Centrid Inlimtl, 271 (2).
l’roviowly rtx:oriltd for Nyastb, Titngtuiyika, and Lnko Kiwu.
Viw. RIIPESTHIS (Grun.) 0. Miill. formii CHASSA 0. Miill.-iL
form wliich
approaches B . muschs (Kiitz.) 0. Miill.
Luke Rudolf, 271 and 2x7. Tn the latter sumplo werc some vcry smiill
intlividuals, only 17 or 18 p long and 7 p wide.
Vur. VASHEIJRCKII0. Miill.
Lokt3 Riidolf, 2x7. Tho ventral lino is straight in tho rnid(llo.
Long. 1%p ; lat. 6-7 p.
I~lIOPAT,OI)IA (:IBHEHULA
J ~ l I O P A J , O l ~ I CHACILIS
A
0. Miill.
1895, p. (it], pl. ii, figs. 6 & 6 .
Lake Rudolf, 221, 266, 287 ; Lako Edwml, 542 ; KainndiL 1,agooii.
Previously recorded for Titngtmyika and Victoria Nyanzi~.
R,T~OPALODIA
HIHUMXIFORMIS 0. Mull. (Text-fig. 1, 1) - P.)
Lake Edwtwd, 512 ; Lake Rudolf, 266, 2x7 ; T,ako Hunyoni, 707 A.
This is one of the Hhopdodias with assymmetric fruutulea which, so far
ILS is itt present known, itro confined to tho continent o f Africir. It occiirrctcl
i ~ sa thick iric!riistntion on tho stems of w;itar-weetls in Lako Itudolf. Tho
brimclied stalks, resembling those of certain C4ornpliontmw were tlt?,scrilic.tl
by 0. Miiller (1905, 1’. lGl), but t,hcy Iiavo riot 1)mn previously figurcd. Nonc
of tho vitrieth recorded froin thtt k’ictoria xysnza w(!rc observed in tho j)rftsctrit.
col Iwtion.
Lcngth o f cell 80-1.10 p ; grt!ittt!st width of valvc 16 1s p.
Prtwiously recorded from h’yasu, Victoriii Kytnzit, ; t r d Til.ngitl1yikn.
~~llClI’AT,ODTA
VENTHlCOSA ((+run.) 0. Miill.
Lake Rudolf, 2x7.
hcviously recorded for Like Nitivasha.
RHOPALODIA VERMTClT1,ARIS 0. Mull. forma nov. I<RCT:\. (Tthxt-fig.1, A-C.)
Lakc Rrtnyoni, 707 A, 720.
Mwgine dorsnli vnlvnrurn recta, non siriuosn.
I n t,hc Iirtwnt forin tlio ttorsirl c w i t o i i r of t,hc r d r c is porf(?ctly straight,
THE EAST .iFRICA?S LAKES : THE ALG.4E
"3
not sinuous as in the type (0.Miiller, 189.5, 111. ii, figs. 10 & I l ) , but in other
respects i t agrees with Miiller's description. In Rhopalodiu ascoidra 0. Miill.
also tho contour is straight, but the apes of the valve is curvod towards the
vontral side, while here i t is not so curved. The very thick gelatinous stalk9
are drawn in toxt-fig. 1, A.
Length of cell 146-24Op (2Oop was i t very common length) : greatest
width of valvs 18 p : width of girdle-face 32-38 p.
Rhopnlodia ?wmicuZoris was noticcd by G. 8. West (1907, p. 162)
on the lake shore of KarorigiL, Kyasa, forming thick, yelIow-hrown, matted
TEST-FIQ.2,
B
A. R . Surirelln hi.qerinta vnr. lunreolala. C . Aeterionelln gmrillimn forma.
AH ~ 4 0 0 .
mas.ses on the back of R beetle (LimmjcJton). In Lake Bunyoni it was foiind.
attached to water-weds on the sliore, intermingled with the firr marc!
abundant R. hirudinifmwtis. Tt was also found hero i n the stomach of A fish
(7'ihpia).
The typo has been previoiisly recordcd from N.Vits:t. Victoria Xyanzs, ttncl
Liike Kiwi.
SITZSCIIIA COMMI'NIS
Lake Runyoni. 729.
Ilabenh.
\-itr. m w i - c i r r , r A A
Itnbc?nli.
264
MISS PLOREXCE RICTl--OAXBRIDUE: EXPEDITION TO
NITZSCHIA
RUNCJARICA Grun.
L:bke Rudolf, 287.
XITZSCHIA
MICROCEPHALA Grun.
Lake Baringo, 106 A ; Lake Gcmgo, 617.
NITZSCTIIA
sp.
Lake George, 617.
STJRIRELLA
BISEILIATA RrBb. var. VUMARIS Meishi-.
Lake Edward, 530, very common.
Length 153 p ; width 42 p.
Vttr. SCB-CONSTltICTA Meister.
Lake Edward,530, 571.
Length 180-300 p ; greatest widt,h 35-44 p ; ribs in 10 p= 1.75.
Vitr. STTRPARALLELAMeistor.
Ldke Edward, 530,552.
Lcmgth 2YO to 306 p ; greatest width 50 to 43 p.
Var. LANCEOLATA, vitr. nov. (Text-fig. 3, A, H . )
Lrike liudolf, 216, 271.
Tmgiorc quam typo, polis plus atknu:itis.
Length 180-3CH) p ; width of vtilvo 28-35 p ; width of girtllo 35-44 p ; ribs
iri 1 0 p . - I circa 1.6.
This v:wir:ty is longer than tho typo and its ostrcrmitios wo moro attenuottrl.
BU~WELLA8p.
T,:& Rudolf, 25'7. Only one individual won.
Class V. CRYPTOPHYCEAE.
CRYPTOWONAS
OVATA Ehrenb.
Lake Naknvali, 812.
Class VI. DISOPHYCEAIS.
GYMXODINIUM
sp.
Lake Nakttvitli, 814. Very rare.
Class VIII. ETXLENINAE.
EIrmExA A C ~ S
Ehronb.
Lake Nakavali, 812, 814 ; Kiizingit Chnnnol, 527.
EUULESAO Y Y U I ~ I Y Schmarda fornia
MINOR
Dofl:mclro (Fritsch & Rich.
1929, fig. 24, A).
Lake Nakavnli, 814. Very rare.
T ? r A c ~ i s T,OKGTC*ACLM (Ehrenh.) Ihij. var. TORTA fonnil,
West and 13rakpau. Fritndi & Rich, 1929, fig.25, 1 3 4 .
Lakc Naknvali. 814.
ibs
in Griqualanil
THE EAST AFRICAN L A K E S : THE ALQAE
265
b A C I ! S PLEURoxECTEs (0.
Mull.) Duj.
Lake Naivasha, 39.
I'reviously rwor(Iec1from Albert Nyanza.
TRACIIELOMOSAS
HISPII)A (Pnrty) Stmein.
Lake Nakavali, 812, 814.
Long. 40p.
Class XI. MYXOPHYCEAE.
(Wittr.) Kirchn.
Lake Jhingo, 106, 117, 121 ; Kazinga Channel, 510, 527 ; Lake Edward,
328, 530, 552, 571 : Lake George, 603. 623 ; Lakc! Nakavali, 813; Lake
Kachira, 824 ; Lake Kijanebdola, 833.
This is certainly the commonest alga in the present collection. The colonies
:we frequently broken through and show gt~ps,thus resembling the figuro of
M . aeruginosa Kutz. given by G. M. Smith (l920), pl. v. fig. 2. The cells we
3-6 p in diameter, and frequently possess pseudo-vilriioles. Sometimes, notably
in Lakes Nakavali and Kijanebalola, tho colonies aro lobate, and are enclosed
in a firm, well-defined sheath, thereby recalling M . rrmrginata (Xenegh.) Kutz.,
but no stratification of the sheath was visible. On the wholo, it seems wisest
to refer all the forms noticed to the species jlos-aqiim.
Prcvioiisly recorded from Npasa snd Victoria Nvanza.
&hCROCYSTIS FLOS-AQUAE
MICROCYSTIS MARGIN ATA (Menegh,) K iitz.
Lake Edward, 57 1.
Elongated colonies 80-90 p long, 4 - 5 0 /L broad. Cclls round, about 5 p in
diameter. Pseudo- m c u oles present. Sheath showing we11- defin od 9trati fication.
APHANOCAPSA
ELACHISTA w . & G . s. West.
Lake Kaivasha, 30.
Previously recorded for this lake.
Var. PLANCTOBICA G. M.Smith.
Luke Nakavali, 814.
Cells 2-3 p in diameter. The shciitli ill tlcfinod. Colonies usually from
40-50 p across.
APHANOCAPSA
DELICATISSIMA W. & G. S. N'est.
Lake Naivasha, 30 ; Lake Nakavnli, 814.
Cells loss than 1 p in diameter.
APHANOCAPSA
GREMLLEI(Hass.) Rabenh.
Lake Baringo, 1 0 6 A ; Kazinga Chsnnol, 510: Lake Edward, 571 ; Lake
George, 603 ; Lake Nakavali, 814.
Cells about 5 p in diameter, frequently in pairs.
The allied A . pulchra (Kiitz.) Rabenh., which shoilld probably be included
in this species, has been recorded from Tiinganyika.
L I N N . JOURN.-ZOOLOQY,
VOL. XXXVIII
19
266
mss
FLORESCP: RICII-CAMBRTDQE
EXPEDITION
m
APRAS~THWCE
sp.
Lake Naivatiha, 30 ; Kaianda Lagoon, very rare.
(!ells bsroly 2 p wide, about twice as long. The few colonics seen comr
now A. nidulnn-9 P. Richter.
CHROOCOCCL~S
MIXIITUS Kiitz.
Lake Edwrird, 530, and Kaianda Lagoon.
GOMPIIOSPI~AERTA
APONINA Kutz.
Lake Ntiivasha, 31.
Previously recorded from Naivasha and Tanganyika.
COEI,OSPIIAEBIUM ~ E T Z E Schmidle.
I
Lako Edward, Kaianda Lagoon.
Previously recorded for Central Africa.
COELOSPHAERIUM
KUTZINQIANIJM
Naog.
Like Naivasha, 43 ; Lake Edward, Kuirinda Lagoon.
W o r d e d from Victoria Nyunza.
COELOSPHAERIUM
MINUTIYSIMUM Lemmerm.
Lake Nuivasha, 30 ; Lake Nakavali, 814.
Cells 1 p, or loss, in diametor.
MERTSMOPIWIATENTTTSSIMALund.
Lake Nakiivuli, 814 ; Lake Edward, Kaiandn Lugoon.
Found in North, East, Equatoriirl, and South Africa.
? ~ACTYT,OCOCCOPSZSRHAPIIIUIOIDES Himsg.
Lake Edward, 571.
Seen only once, and as no more could be found on repeutcd examination
the determintition has not been confirmed.
CALOTHBIXBREVISSIMA ( 2 . s. West-" doubtful spwins-var. MOXTTAIFO~)d~S
(:hose. (Text-@. 4, C, D.)
Lake Nakavali, 812.
Short lengths of cells, 4 p wide, occurrcd singly, or two or three together,
in the sheiitli of tin 0scillatori;tceous alga, mi the weedy shore of Lalie Nukavali.
The 1ietmocystR were basal, spherical, iind slightly largt?r than the other cells.
It is probably merely a young stage of another spocios. It shows n certain
rovemblance to Proterendothrix ,9colpcoirlpa W. & ( 2 . S. Wost, but the trichomos
iirc less tapering.
Yreviously recorded for Tangnnyika iind Victoria ~ Y i b l l Z l L .
CALOTHBIX
app.
Lake Rudolf, 220.
Tn an incrustation occurring on water-weeds from this lake, them occurrc~d,
associated with Cyngbyn lwtea, a Novtoc and a Cabthrix, both in an imrnatum
condition, 'and, a t this stuge, not determinublo. Terminal 1icteroc:ysts were
present in the Cdothriz, but there wcre no spores.
Other species of Cdothrix occlirrtd in a fragmentary condition in 1,:tkc
Nakavtvali, 812, in C'rater Lake A, 271, and in Lake Goorge, 617.
THE EAST AFRICAN TAKES : THE AT.G.4F:
SCYTOX’EMA
sp.
Lake Rudolf, 271.
Fragmitnts only. Trichomes !)-I0
p
267
widn : filaments I+I5 p.
CLOEOTRICHIA
NATANS ( H d w . ) RibhTih. Rich, 1932, fig. 20, A, n.
Lake Nxivndia, 39, mid from tho woedy oast shore.
Spore, from 14-16 p wido ; from 3 - 6 6 p long.
Previously rcrordod from plankton in the Transvad, Tangangikn, and Victoria
Nyanza.
RIVULARIA
BIASOLETTIANA
Menegh.
Lake Rudolf, CrzLter Lake A, 271.
Fragments only. Shoaths yellow. Trichomo 8 p wide at tmw, tapering
above to 4 p.
Recorded for Lake Naivasha.
? MICROCHAETECAPENSIS Hodgetts. (Text-fig. 4, E-G.)
Lake Edward, 542,from an incrustation on water-weds.
Filaments 4-5p wide, excopt a t the barn where they may be 8 4 p .
“richome about 3 p, slightly attenuated a t tho tip. Cells shorter, or a little
longer, than broad ; terminal cell with a rounded apex. Heterocyst tcrminsl,
basal. somewhat egg-shaped, or conical, with the narrowor end pointing
downwards; 6-7p wide, 9-lop long. The sheath (which does not turn
Mue with chlor-zinc-iodide) is prolonged backwards, bolow the heterncyst,
forming a short tribe (text-fig. 4,F) or shrivelling to a point (text-fig. 4, E).
This appearance may be due fa part of the common sheath being dragged away
with tho filament, but this could not be established in the matorial to hand.
I place this alga tentatively in the above species mainly on account of the
shape of its hoterocyst ( s ~ eHodgctts, 1926, fig. 16, A, R), but its cells are
longor, and no spores were prosent.
Hodgetts’s species was growing on tho sides of a glass tank in the laboratory.
? MICROCHAETE IJBERRIMA N. Carter f. MINOR s.Curter, 1926, pl. i, figs. 1-4.
L&e Xi~kavali,812 ; Lake George, 617 ; Lake Kachira on Hladtler-wort.
Filaments thrce or four together, 10-14 p widc. Trichome about 8 p wide,
cells almost square. Intercalsry hc?terocysts elongated, almost rectangdnr,
16-22p long, somctimes two together. No spores were seen, hence this
determinution is rather doubtful ; the spcimen agrees very closely with
Carter’s figures.
The allied M . 7:iolncen Pr4my has 1)ecn recorded from standing water in
French Equatorial Africit.
XOSTOC SFPI).
I,&(:
Naivashib, 39 ; Lake Rudolf, 220 : Lake Sttkuvuli, 812.
Tn Lakc Rudolf tho species present ncciirred in small mud-like patches
on the stems of higher plants. It was in an immature condition intermingled
with L!/7qD?yaZutea and a spwics of (hlothrix. Cells 4 p wide, torminal cell
blnntly conical ; heterocyst spherical. 6 p in diameter.
19*
268
MISS FLORENCE RICH-CAMBRIDGE
EXPEDITION TO
NODULAKIA
SPUMIQENA Mertens.
Lake Creorgo, 617, very rare.
Trichome 9 p wide, no sheath visiblo. S o ~ S ~ I I C Z O - V ~ L C I I O I ~ ~ S .(Vnr. ??.acuolriln
I+itsch & Rich has been recorded from Griqwiliind West and t.110 'L'rtLns\.;tid.
Froin Tanganylka three species of Nodulnrin h a w been recorded, hilt not
the present one.)
ANAUAENA
spp.
Like George, 617.
(a)With pseudo-vacuoles. Colls 4 p wide ; hetcrocysts round or clongntcd,
6 -6 p wide. Ko spores priwmt,.
( b ) Without pseudo-vacuolcs. Cells nnd hcterocysts :I little wider. So
sporcs present.
ANARAENOPSIS
CIRCULARIS (G. S. U'est) Wolosz. & Millor, e m e n d . \I7.
R.
Taylor (=Anabaena $08-aquae (Lyng.) BrCb. viw, circiiltiris ( i . S . West).
West,, (+.S., 1907, pl. x, fig. 3,a,c : Taylor, U'. M.,l!M, PI. sxsix, figs. 5-10.
(Text-fig. 3, B, C.)
Lakc Edwwd, Kaianda Lagoon, rmc. -4lso obmrvecl in Lake Nakuru,
Miss P. Jenkin's samples.
Somo doubt exists as to the validity of the genus A?&enopsis,
and
Professor Hharadwaja *, whose manuscript I have been privileged to sec,
has recently given reasons for discarding it us a distinct genus, i d rc:-t!stablisliiiig
it as a section (as distinct from the section Emnubaena) of the genus dnabncntc.
I n the present paper, howover, I am following F r h y and Geitler in retiiining
the genus Annl,mnoysi.s to include those anabiwnoid forms which possess
i t terminal heterocyst a t both ends of the filament.
On oxumining West's muterid of the above spcics from Titnganyika T cam0
to the conchision that three different algae (two of which m e spirally coiled
and occur in the sumples now under considertttion) ucrc included undw t h
ono nanie. Aftor writing the first. dridt of this 1)itl)e:r T found that Professor I\'.
K. Taylor (1932) had already come to t,he same conclusion, iintl I I M ~n t ~ n i c d
those that were spirally coilcd as follows :(1) The one with elongated cells as A . circularis (in my draft paper I had put
this tentiLtively in i~ soyarih species, considering thiit tho narno circu.Zaris
should be better retained for tho A rubatnopsis with almost spherical colls
and of which Woloszynsku had doscribed a var. ja.~~anico-avariety, by thu w;~y.
tllitt previously I had suggested shoilld 1)o considered merely as a f o r m t).
( 2 ) The onc with almost spherical cclls as an Africun form of Ariail,ar!,nc~~)si.s
Arnoldii Aptekarj 0.
The trichomcs in the samplc from the Kuicmda Litgoon itre short, spiriilly
wound, making usually onc: m d :I qwirtrr turns, thoiigh occasionally up to
* ' Anndn of
Bot.Rny,' 1933, xlvii, p. 117 r f a q .
Rich, F.,1 9 3 2 ~ .
The coll.~in tht+ 'Tangmiyiktt riiateritrl wrre micl by \Vcnt
oblong.
t
to
lw cithcr nplicrical or
‘THE EAST AFRICAN LAKES: THE ALGAE
269
as many as four or five. Cells 4-5 p wide, elongated, two to four times as long
as wide, without pseudo-vacuoles, but with a conspicuous granule in each (see
text-fig. 3, B, C). Heterocysts solitary, one a t each end of the trichome, circular
or, less commonly, elongated, 3-5 p wide ; also containing onu or more granules.
Spores intercalary, solitary, ellipsoidal, with thickened walls ; 7-8 p wide,
10-11 p long (text-fig. 3, B). The spores were not observed either by West
or Taylor.
West mentions the occurrence of the characteristic granule, ‘ gas-vacuole ’,
but figures it only in the forms with elongated cells ( i s . in A . circularis and
A . Cun?h.qtonii according to Taylor). This alga agrees with West’s figures,
pl. x, 2 a and c, though not with b and e.
Previously recorded for Tanganyika, and present in Lako Kakuru.
ARNOLD11 Aptekarj, forma, ‘African form ’, Taylor (=Amhaem
ANABAENOPSIS
jlos-aquae (Lyng.) Britb. var. circularis G . S. West). Taylor, 1932, pl. xxxix,
figs. 11-14 ; West, 1907, pl. x, fig. 2 b ; Rich, 1932 a , fig. 5, A-C.
Lake Rudolf, Alkalino pool on Perguson Spit, 257, very common, associ;tted
with ArthrospiTa platensis, but more abundant. This association is similar
to that found in Lake Elmenhita.
Width of trichome 8 p , number of turns of spiral one to six. Hsterocysts
usually circular and 8 p in diameter ; sometimes a little longer. Spore 10 p
long, nearly as wide ; Taylor found no spores in his Philippine material.
Pseudo-vacuoles were occasionally observed.
It differs from the preceding in (1) the greater width of the cells, (2) their
shorter length.
I n view of the work of Professor Taylor the specics I described in 1‘332
should be named A . Aroldii, forma.
Previously recorded for Tanganyika and Lake Elmenteita.
AXABAENOPSIS
TASGANYIKAE (G. S. West) Wolouz. & Wller. (Text-fig. 3, A.)
Lake R’aivasha, 30 ; Lake Edward, 530 ; and Kaianda Lagoon.
Trichome barely 3 p wide ; heterocyst the same width, 5-56 p long.
I n specimens from the Kaianda Lagoon as many as five and a half turiitj
to the spiral were sometimes observed.
Previously recorded for Tanganylka and Lake Nakuru. (In Rich, 1932 ( a ) ,
p. 261, A . circularis has also been included under this name.)
SPIRULINA
MAJOR Kutz.
Lake George, 617.
Previously recorded for Tanganyika.
SPIRIJLIKA
SUBTILISSIMA
Kutz. Gomont, 1893, pl. vii, fig. 30.
Kaianda Lagoon.
Recorded for Tanganylka.
ARTHROSPIRA
PLATEHSIS (Nordst.) Gomont (=Spimlinu platemis (Nordst. )
Geitl.) Rich, 1932 a , fig. 4, A-F.
Lake Rudolf, 211 B, 257 (a) ; Crater Lake B, 269 ; Crater Lake c, 273.
270
MISS FI,ORENCN HICH--CAMHKID(:E
EXPEDITIOS T o
Vurious forms of spiral were observed, similar to those found prwioL1sI.Y
in Lake8 E1meriteit;i and Niikurii, iind thc Crater Luke netir SiiivttAa (Kicll,
1931, pp. 75-!I). The width of‘the trichome wiis comnionly 6 p, and the number
of turns of thc spiral varied from two or three t o fourteen. It is noticeable
that in the present collection this Arthrosyim (or h’pirulirm) was found only
TEXT-FIG.
3.
A
C
F
G
H
E
A. Anabaenop8,aie tanganyikne. n, C. A?tabaempia circulnri:, ; 11.. IieterocyrJt ; a., spore.
D-H. Lyngbya Lagerheirnii. 1. Lyngbya circumreta. All x about 750.
in the alkaline pool on Perguson Spit, and in crater lakes €3 nnd C (all on
Lake Rudolf) ; the alkalinity of t h w pieces of water was greater than that
of Lake Rudolf itself, though less than that of Lakes Elmenteita and Nakurri
and Crater Lake.
Yorma MINOR Rich, 1'33'2, fig. 4,U,H.
Lake Rudolf, 211 B.
This narrow form, 4 p wide, occurrnd sparingly in the abovo sample, Tho
width of the spiral was ebout 20 p, and thero w0re soldom more than five turns
to the spiral.
Vauch.
Ltke Naivitsha, from wccdy Eitst sliorc.
Width of filament 26 p.
Widely distributed in Africa ; rocordod from Albert Nyalliit.
OSCILLATOSIA PRISUEPS
~ S C I L L A T O l Z I ATENUIS
Ag.
Lake George, 617.
Width 5 4 p, cells varying in longth from 2 - 5 4 p, with a slight constriction
between. Two rows of gritnulun across the partitions wore vixiblo in some
individuals. Extremities slightly curved.
Kccorded for Victoria Nyanzs, Tangenyikii, and Albert Syanza.
(Ag.) Ciomont.
Lake h r i n g o , 106 ; Lake Rudolf, 266.
Recorded for Tenganyika.
PHORMIDIUNAITTI-MSALE
PHORMIDIUM
AMRIGIJUM Gomont, 18!)3, pl. v, fig. 10.
Lake George, 617 ; Lake Nakavali, 814.
I n tho specimens from Lake Nakavali pseudo-vacuoles were obsorvud.
Recorded for 'Tanganyika.
Gomont, 1893, pl. iv, fig. 16.
Lake Bunyoni, 707 A.
Recorded from Tanganyika.
~'HORM~UIUM
YOVEOLASUM
PHORMIDIUM
MOLLE Comont, 1893, pl. iv. fig. 12.
Lake Rudolf, 248, 250.
It occurs mixed with Horniidium subtilo.
Width 2-3 p, cells nearly as long as wide ; end-cell rounded.
YHORMKUILJM
MCCICOLA Kaumann & Huber. (ieitler, 1932, fig. W37.
Lake Raringo, 106. Intermingled with disorganized colonies of Nicrocystis
30s-aquae.
The filaments are short, generally straight, though sometimes slightly
curved, and consist usually of only three or four cells. The cells are barely
2 p wide, three or four times as long, with rounded ends. At first it was thought
that the short filaments observed in this sample were merely the hormogonilt
of some Phormidium growing in the littoral regions, or :it the bottom of the
lake, but on further consideration they were found to fit in well with the above
species.
Not previously recorded for the continent of Africa.
272
MISS FLORENCE RICH-CAMBRIIXE
EXkEDITlOX TO
(&]I).) (hllotit, 1893, pi. iv, fig. 20.
Lake Naivasha, 31.
Not recorded for the Grcut Lakes of JCquatorial Africa, but h o r n froin
other parts of thc continent.
? LYNGRYA
HIESONYMUSII
Lommcrm.
Lake Edward, 522.
Trichomc 14 p wide ; sheath incrusted ; cells very short, with granular
contents.
This determination is not conclusive, as only a vcry few LiliLments wen!
obscrvd.
LYNGBYA
LIMKETICA Lemmttrm.
Lake Kachira, 824.
IIiolated filaments, not inore than 2 p wicio ; sheath well defined ; cells
about as long as broad. End rounded. The contents not well preserved.
Rccordetl from Tanganyika and Victoria Nyttnza.
rAE”(2MYA LUTEA Gomont, forma nov. (cj. (iomont, 18‘33, pl. iii, fig. 13).
Lakc Itudolf, 320 ; Lake George, 617 ; Lake Edwtird, 707.
Puullum angustiorc quam typo.
On wooden piles along the shore of Lake Edward there wits observed a thick,
tough, brownish growth, about 1 cm. in thickness, which was found to consist
almost entirely of ib form of L. lulea. The sheath was well dcfinod and stained
blue with chlor-zinc-iodide. The apical cell was rounded, and thickened
slightly on the outside. I n most of the c o l l ~there were from one t o four
rolntively largo granuleti. The trichomes were regularly 2 p wide, of‘ it pale
blue colour. The present form is a little narrowor than the type, tho width
of which is given as from 2.5 to 6 p.
Not previously recorded from the Great Lakes or Equatorial Africa.
PH0HI)IIUIUM VAT,DERIAKUM
Section S I Y M W O L K ~ : ~ .
LYNGBYA
CIRCUMCBETA G . S. West. (Text-fig. 3, I.)
Lake Kaivasha, 30 ; Lake Nakavali, 812, 814.
Filaments nearly 2 p wide, coiled in circles of from 40 t o 60 p in diameter.
Cells only a very little longer thitn broad, apex rounded, A t the septa oiic
or two granules are frequently observed, in this respect reHemhhg the spirally
coiled L. bipuilctata Lemmerm., L . umtorta Lemmerm., and L. LQgerheirnii
Mobius. G. S. West, in his account of the Algae of Victoria Nyanza (1907,
p. 174), remark6 that the Lyngbya circumcrida found by him in this lake comes
near L. contwta, but differs ‘ in the hoop-like coiling of its filaments, which
are also of greater thickness, and in the much shorter cells.’ He docs not
mention thc existencc of gritnules, but I do not find that thew are always
present. From L. bipunctata the Lyngbya now under notice differs only in
its shorter cells, thosc of L. bipu,nctata being from 3.5 to 5.5 p in length. Tilere
is evidently somc confusion between the species of tho spirally coiled Lyngbyas ;
text-fig. 3. T, inakes clear which one is here referred to.
Previously recordd from Victoria Nyanza and LiLke Nativeslia.
THE EAST AFRICAN L A K E S : THE ALGAE
? LYNGBYALAGEBHEIMII
(Mobius) Gomont.
(Text-fig. 3, U-H.)
Lake Edward, 530, and Kaianda Lagoon.
273
Ostenfeld, 1908, fig. 2.
c "
D
Uncertain Blue-Green Algae. A , U. LyjLybya sp. ( 1 ) . C , D. Calothrix brevissima V81'.
?nmilifor?>iisin sheath of Lyngbya sp. ( 1 ) . E-G. Micsochaete capensis (?). All except
U x750.
Filaments in rather small coils or loose irregular spirals. Diamobr of
coils from 12 to 30 p. Cells less than 1 p wide, 2-3 p long, ends rounded.
This alga differs from the preceding in its smaller coils, and in the possession
of narrower and longer cells. It differs from L.contorta Lemmerm. in its smaller
cells, and the absence of granules. Ostenfeld (1908, p. 333), in describing
271
NISS FLORENCE HlClI-CAMHHIT)(1E
EXPEDITIOK TO
the Lyqbyu found by him in the plankton of Victoria Nyanza, said he
considered that both L. circumcreb and L. contorta d~ouldbe included in thc:
spwies Lagerheimii, but West (1909, p. 246) did not agree with him, and Goitler
(1!132, pp. 1043, 1044) still k c e p these species distinct. Lemmermcmn's
figures (1898, Tab. v. figs. 10-13) of L. contorta are certainly w r y likc thc:
present form, but so also aro Ostenfeld's clmwings of L. Lcsgerhei.)nii (see
l~bove). On the other h n d , comont's figures (18'33, pl. iv, figs. 6 & 7) iirc not
much like it, representing a wider filament. West stated t h a t he was somewhat
in doubt about his own determination of L.contortu in Lako Albert, but added
that in the large African lakes there were two ,apparently distinct speci(:s
of spirally twisted Ly1igbya.s. They tire probably the same two that are found
in the present collection.
Previously recorded from Victoriti Nyanza.
An Oscilbtorinceous ; L I not
~
well preserved, and therefore not definitely
determinable. (Text-fig. 4, A, H.)
T,ake Eakavali, 812.
Thin dgtt occurred, mixed with il species of' Cololhrix, on the wtwdy ahorc
of Lake N a k a d i .
The filaments present were broken off, and only very rarely wan the apex
Seen (text-fig. 4, A). The material was badly preserved and the cells wero
often found to be Reparated from one another by rather large gaps, and werc
frequently misplaced, lying vertically or oblipuely in the sheath (same kxt-fig.)
Tlie fililmonts, 14 to 20 IL wide, showed many twists and turns (text-fig. 4, U).
'l'ht? sheath was coIourleRs, often rather thick and lamcllose, and wits t h w n
out a t the a p x , wliure i t had u fringed appearcmce ; it W ~ oolourless,
H
and did
not turn bluc with chlor-zinc-iodic~~!.The trichome WILY10-14 p wide, and the
disc-shaped cells were usually only about 4 p long. The apical cell was rounded.
Contents granular.
Ln many respects this alga showed resemblances t o Porphyrosiphon Notarisii
Kiit,z., but dilfered from it in the ontire absence of any red coloration, and
in its uniformly shorter cells and narrower sheath. W t l e r (1932, 1). 9x6)
considers that tho retention of the genus I'orphyrosiphon is purely conventional.
The alga now figured may prove t o be a L y n g b p , but it cannot bo I)roIwrly
determined from this materid.
LITERATURE
CITED.
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UEFLANDRE,
(2. 1924. Additions a la flow algologique des environs do Paris. Bull.
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CAXTEH, X. 1926. Freshwater Algae froni India. Rec. Bot. Surv. India, ix.
E ~ L A N D S S O X , S. 1928. Diatomocn aus Afrika. Svensk Botanisk Tidekrift, Bd. xxii.
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E'RITSCH, P.E.,& RICE,F. 1924. Freshwater and Subaerial Algae from Natal. Trans.
Roy. SOC. S. Africa, xi.
lL, & lilcrr, F. 1!J29. Freshwatcr Algae from Griqualand West. Trans. Roy.
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-,& STEPHESS,E. L. 1921. Yreshwatcr Algae, I I I ~ I I I ~from
Y
the Trrtn8kci Territories.
Trans. Hoy. So(..S. Afr. ix.
G a i , r ~ l c ~L.
c , 1!)32’. Cyaiioplrycea~(Blaualgoii). Leipig.
GUMVST, M. 1093. hluiiographic rles O w i l l a r i h . Ann. Bci. S a t . Uot. xv & xvi.
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Soc. S.Afr. xiii.
tLr:uE:H-PE:sTnLozzI, U., & NAWJIASX, Y.
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pp. 67-76.
LENMEHMANK,
E. 1898. Forschuiigsber. d. biol. Stat. i i i P h n , vi.
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F. 1912. Die Kicselalgen tier Schweiz. Hcrno.
J l i j L L m , 0. 189.5. Hhopalodia. Eiiglcr’s bot. Jahrb. xxii.
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-.
1903-1910. Hacillariacecn trus doni Nyassalande untl oinigon beriachbartoil
Ucbicten. Englor’s bot. Jahrh. xxxiv-xlv.
SYGAAIW,
U . 1932. Freshwater Algae aiid IJhytoplankton from tho ‘l‘raiisvtutl. Trans.
~ J Y SOC.
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S. Afr. xx.
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Jahrh. xli.
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PASCUEII,
A. 1913 et 8 q . Die Siisswasserflora Dcutschlands ctc. Jena.
I ~ I C HI?.
,
1931. Kotes on Arthro.yira platen&.
R e v . Algologiquc, vi, pp.*78-79.
-. 1932. Phytoplankton from South African Pans and Vleis. Trans. Roy. Soc.
8 . Afr. xx.
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Nat. Hiat. x, no. 57, pp. 233-262.
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Englcr’s bot. Jahrb. xnxii.
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iimorafrikanischer Seen. Hnglor’s bot. Jahr. xxxiii.
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--.
384.
1904-1912.
--.
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