Notice of new living Crinoids belonging to the Apiocrinids.
THONSON,
LL.D., D Sc., F.R.S., F.L.S.,
By Sir C. WYVILLE
F.G.S., &c., Regius Professor of Natural History in the University of Edinburgh, Director of the Civilian Scientific Staff
of the Challenger ' Exploring Expedition.
LRead June I, 1576.1
ON the 25th of August, 1873, on our voyage from St. Vincent t o
Bahia, we sounded in 1850fathoms with a bottom of "Globigerinaooze," and a bottom-ternpcrature of 1 O . S C., in lat. 1" 47' N., long.
24."26' W., about 300 miles east of St. Paul's Rocks. The trawl
was put over ; and when recovered in the evening it yielded us an
unusually large number of interesting forms :--with many others,
several large specimens of ft fine species of Limopsis ; several Brachiopods; a small Umbellularia; some remarkable Bryozoa ; several
specimens of a large species of Xalenia, differing apparently in other
characters besides its much greater size from the widely distributed 8.varispina ; an entire specimen of a beautiful stalked Crinoid which I shall describe under thc name of Bathycrinus aldrichianus; and some fragments of the stem of another Crinoid,
Hyocrinus bethelliicnics *, of which we afterwards took one or two
complete specimens and several fragmentary portions, at Station
147, lat. 46" 16' S., long. 49' 27' E., 30 miles to the westward of
Hog Island, one of the Crozet group.
I now give a preliminary sketch of these two new Crinoidal
forms, in the hope of preparing a detailed description of these and
of the large number of undescribed Pentacrini which were among
the most interesting t)f our captures, on my return.
I described and figured in the ' Depths of the Sea ' (p. 452),
under the name of Bathycrinus gracilis, a delicate little Crinoid
which we dredged in the ' Porcupine' from a depth of 2475 fathoms
t o the south of Cape Clear. I think there can be little doubt,
from the structure of the stem and calyx, and from the form and
* As the stalked Crinoids are perhaps the most remarkable of all the deepsea groups, both on account of their extrenie rarity and of the special interest of
their palzontological relations, I mean to associate the names of those naval
officers who have been chiefly conceived in carrying out the sounding, dredging,
ancl trawling operations with the new species whose discovery is due t o the
patience and ability with which t h r j have performed their task. Lieutenant
Pelham Aldrich was first lieutenant of the ' Challenger ' during the first two
years of her commission ; he is now with Captain Nares as first lieutenant of
the 'Alert ,' Lieiiteiiant George R. Bethell, I am g b d to sap, we haTe stlll wit11 us.
LIBN. 3oiwx.--7,00rAoctT, Tor,. XIIT.
(i
I:
SIX
c. w v r , r J b ;
TIIOXSOR ON SEW L I T J W
scAulpture of the plates: and joints, that the first iiaiiied of tlie
i 11o species iiow to be noticed iiiuvt be referred to t h e same genus
‘A‘hcrc is, ho\\-e\er, one niarked difference between the two : i t 1
our specimen of 27.p n c i l i s , \T Iiich looks as if i t were full-growi.
the t e n arms are perfectly simple, and there is no trace of piuiiulw,
n hilc in B. nldrichinnzis the piniiules are d l developed.
RsIliave already saicl(Zoc. cit.), strong resemblances in tlie struc1 tire of the stein, iii the structure of t h e base of the cup, and in tlw
foriii and arrangcmerit of thc ultimate parts of t h e arnis associate
Dathyciiius n it11 RhizocriizzcP; but :lie cliffdrences b e t w e n the ti1o
genera are very obvious. Tile radial asillary joints, nhicli i n Z h i =ocrinzcs are contracted to support a single first brachial, are here
t~xp:intled aid benr two orticulatiug surfaces giving origin Lo tn t i
:wins ; so tliat, :is i n most Criuoicla, tlie m i n b e r of priinary tlivisioiis of t h e aims: is ten. The strneture of’ the cnp a i d of tlic
iipper part of t h e stem, while es~eiitinllythe bame i n both, is c l i f Y L r r . i i t in detail : in R ~ ~ Z O Cthe
P~
i’unnel-shaped
I I Z C ~ piece formed b j
lie coalescence of the basals x i t l i the fused first radials abovib
:iud the diIated upper joint of the coalesced upper joints of tlic
hteiii beneath, mulies u p a large part of t h e cup ; while in l’o
/hycriizus the stem barely enlargcs a t its junction with the iwp,
tlie ring formed by the basals is very snial!, and tlie first rathi.
;ire free from the basals, a n d often free from one another. Tlir
ciral plates, ~ l i i c hare conspicuous in R ~ ~ Z O C &are
? Zabseiit
LS, I II
1:nfhycl.ilZus.
I€yocriims is a totallp different thing ; but, as I\ e shall see lie;+
after, it presents certain geiicrai reqemblances aiid even cei
specixl correspondences in structure 11liicli seem to associate ( I
:II so wi tli Jihizocrin zis.
There secnis little doltbt t h a t R7/izocvimss f i n d s its neare;.t lriioii i i
ally in the chalk mid tertiary Bozc~yuetlicri~~us,
aiid t h a t it muht
be referred t o the neighbourhood of the Apiocrinida, 1Vc.i-e it
not that Bntl~yen’nzcsand Hyociii~zisarc so cviclently related to Uhizocrinm, the characters of the >ipiocrinid:e :we so obsciire in tllc
tn o first-named genera t h a t one would certainly have s c a r c e l ~
been inclined to associate them u ith that group.
T h y are both coniparatively sinall forins ; mid although the3
iiot slioiv t h e peculiar tendency to irregularity i n the iiuuibcr of
their principal parts which we find in Rhizocrinzis, t h e i ~ .c a l ~ c
arc sinall in proportion to the sim of the s t ~ n iSO
, t h a t tticre i, st111
;I cwnipar9tii ely rxccssir c d e w l o ~ ~ ~ of
n cthe
~ ~\-cgetati\
t
\j
(L
CRTNOIDS UELONQINO TO THE .\PIOCRINIU.X
Fig. 1.
3)
S I R C. WTT1LT.B THOVSON O X SXI’ 1,IVIXG
311 Bathkycrinics nZd?*riehinnzcs(fig. 1) the stem is, i n full-qo\vu
spcciinens, 200 to 250 millims. in length, and about 2 millims. in
tiiaineter across the enlarged articu1,iting end of a joint. The
I O ~ I ~ Cstem-joints,
S~
from about the middle of the stem d o ~ n \ v a r d s .
harc a length of 4 millime. ; and they rapidly shorten towards tlw
l~aseof the cup. They are dicebox-shaped, and have their eiidc:
brcellecl off on different sides alternately, for the accommodation of
masses of muscle. Towards the base of the stern, a few strong
jointed branches coiiie off and form a sort o f iinperfect root of
attachment. The cup consists of a series of b a s h which are
soldcrcd together into a sinall ring, scarcely to be distinguiulietl
froin the nppcr stem-,joint. Alteriiating s i t l i these are five largv
i rimgiilnr first radials : these are often frec ; but in old esainplc~
t h c j :dso are frequently nnkyloped into a funnel-shaped piece
’l‘hc sccond radials are articulated to the first b y a true joint n i t 1 1
ong bands of contractile fibre ; they are broad and flat, with n i l
ttlevatcd vertical ccutral ridge nhich is continued down upon tlw
first riidials (though in thew it is not so marked), and lateral r i n g like exteiisioiis 11hich CurVe up a t the edges and are thus slight]!
holloned out \crtically on cadi side of the central ridge. I n tht.
third radials or “radial asillarics,” which are joined to the secoiitl
by a s j zygy-, the upper border of the plate is nearly strnight, bill
it is divided into two facets for the articulation of the firgt ti\ ( 1
bracfiials. Thc ridge is continued from the secoud radial to aboiit
tlir i~iiddleof the third, \There it divides into two, and its brandic,
pais t o the insertions of the brachials t o be continued along tire,
Iiiitldle line of the arniB. The wing-like lateral proccsws arc c*oiitiuucd a1011g the sidtls of the radial axillaries and along each sit[(.
of at least the first threc brachials. The arms are ten in niiniber
In the larger specimens Iliey are about 30 milliiiis. in length, :iid
consist of from forty t o fiftyjoints. The first and second and t h r
fourth and fifth brachials are united by syzggies ; and after that
Byzygies occur sparingly and at irregular inter\ als along the arins.
There are no pinnules on the six or seven proximal joiuts of t h e
amis ; but toaards the d L t d eud there are usually about twenty
iri two alternating rows ; the number and amount of developmeilt
of the pinnules seems t o depend greatly upon age, and not t o be
very constant. The arms and the pinnules are deeply grooved
nithin ; and along the edges of the’groores are ranges of imbricated
rcriiL‘orm plates, €coirstsatc and very delicate, much reseirtbIii~g
The disk 1.
thosc in t h e corre~liondingpo>itioii in Riiizoerimis
embrano us, wi tli scat tci ed cdeareoiis granules.
The iiiouth is snbcentral ; there aie no regular oral
plates; but there seems t o be a deteriiiinatiou of cnlcareons inntter t o
five interradial points round the mouth,
where it forms little irregu1:rr cillcareOUM bosses. There is an oral ring of long
fringed tentacles ; aiid the tentacles arc
long and well iiiarlced aloug the radial
canals. The excretory openiiig is on a
low interradial papilla. The ovaries are
borne upon the *is or eight proximal
piiinules on c:ich nrin ; they are short
and roiiiided, resenibling much in forin
those of Antedon rosnceus. B a t h p i nus appears to possess ail asseriiblage
of characters in some respects intermediate between Rhizocrinus and the
pentacrinoid stage of Aiitedon. I
reserve a full discuasioii of its spsteiiiatic position until I have ail opportunity of describing it inore in detail.
It seems t o be widely distributed ; we
I m e detected fragments of’ it at at
least six or seven stations in the
Atlantic aiid the Southern Hen.
Zyocrinus be/?tellianzrs (fig. 2) has
niucli the appearaiice, a i d i i i some prornineiit particulars it semis to liacc
very much the structure, of the palaeozoic genus Platycrinus, or its subgenur,
Dichocrinzcs.
The longest portioii of tlie stein
which we dredged was about 170 millims. in length ; but the basal part was
wanting, and we haw no meaus ot
ascertainhg what may have been its
means of attachment. The steni is
~ n u d more
i
rigid t h m that of Bath/c r i r z u ~aiid
~ is made u p of cylindricirl
111
Pig. 3.
52
b I l 1 0. \Vk \ ILL>, TLIOMSON ON NE\V I.1\ 1 N G
jaints, which are united to one another by a close syzygial suture,
the applied surfaces being marked with a pattern of radiating
groows and ridgeti like those of 80 many of the fossil geiiera, and
like those of the recent P e n t n e h i i . The joints becoinc short aiid
very numerous towards the base of' the cup.
The head, including the calyx and the
arins, is 60 millirns. i n length.
The cup
consists of two tiers of plates only (fig. 3);
the lower of these, which niust be regarded
as a ring of basais, is formed as in some of
the Platycrinidz, of two or three pieces : it is
difficult t o make out which with certainty ;
for the pieces are more or less fused, and the
junctions in the mature animal are somewhat obscure. The second tier csnsists of five
radials, which are thin, broad, and spadeshaped, with a slight blunt ridge running
up the centre and ending in a narrow artic.ulating surface for a n almost; cyliiidrical
first brachial. The arms are five in number,
they consist of loug cylindrical joints deeply
grooved 1%ithin, and intersected by syzygial
junctions. The first three joints in each
arin consist each of two parts separated by
a syzygy ; the third joint bears at its distal
end an articulating facet from which a
pinnulc springs. The fourth arin-joint is
iutersected by two syzygies, and thus consists of three parts ; and 80 do all the sucweding joints ; and each joint gi\es off a
pinnule froin its clibtal end, the pinnules
arising from either side of the arm alternately. The proximal pinuules arc very
long, running on ncarly t o the eiid ofthe arin;
aiid the succeeding piniinlcd are gradually
shorter, all of them, 1io11ever, running out
nearly to the end of the ariri, so that distally
the ends of the five arins aiid the cuds of all
the pinnules meet nearly on a level. This
i* an arraiigeincnt hitherto ciitirely 1111kiionn in receut Clriiioids, although we hai
smiclhing verj claw to it in mine npccic+
(1
C'EINOIUS YELONGING TO THE: APIOG'IIINID E .
53
yalBozoic genera Poteriocrinus and Cyatlzocrinus ; here, 1
believe, however, the resemblance between Hyocrinw and the
early fossil forms ends.
The arms and pinnules are deeply grooved within ; and the
grooves are bordered on either side by lines of imbricated, closeset, reniform, fenestrated plates, closely resembling those of RAizocrinus and Bathycriims.
The peripheral part of the disk is paved with plates irregular
in form and closely set (fig. it) ; round the mouth there are five
very strong and definitely shaped valves, slightly cupped above
and marked beneath with deep impressions for the insertion of
muscles. The valves are pointed, and close over the mouth, forming a very perfect five-sided pyramid. The anal opening is on a
short plated intorradial tube.
of the
Fig. 6.
Dish of Hyocri~zusbefAclZiccizir~,Wy. T, Eight times the 11nli1ral side.
The mouth opens iiito a short slightly constricted esophagus,
hich is succeeded by a dilatation surrouudecl by bro\li u glandular
ridges (fig. 5 , d, e ) . The intestine is very shorf, and coutracts
rapidly to a small diameter (f); the nIiole alimentary tract f o r m
a single simple loop. Round the esophagus a so:ne\rhat ill-defiiied
vascular ring ( b ) , which may possibly be continuous with tho bodycavity, gives off opposite each of the oral plates a group of four
tltbuliir tentacles ( c ) ; and h e s of siniilm tentacles of sinaller
\\
i\rraI>gei~wntol' thc soft l~~ri'ts
in Kyoci.i,tus bethcliimit,~. rr, or:i1 \al\-es :
6, or:,t Yascular ring ; c, oral tri1.taclea ; d , e, iiiirer ~ S I J W ~of'the crsop!~ugu;;mil
~ t o l ~ ~; af.cintestiiie
l~
; g, loose arcolated coiiuectiT-e tissve. Eight tinws tile
natural size.
The assemblage of characters connected with the disk and soft
parts thus shows a considerable resemblance between Hyocrinus
and Rhizocrinus. M y strong hipression is that the mode of' 1211trit,ion of the Cynthocrinidfe, and consequent,ly the structure and
nrrsngemeut of their disk, was essentially different from that of
all the yet known living forms ; and I think it probable that when
we have an opportunity of studying the structure of I p Y o c i k l s
carefully, we shall find that its striking resemblance t o P1afyci-iPLUS is in n great degree superficial.
The following are, I believe, all the Crinoids, referable to the
Apiocrinidz, which w e have hitherto met with during our Jeepsea explorations :R h i a m k u s lofotensis, Sars.
Bntbycrimrs nlchich iwr us, sp, 11.
B. pYlciIis, Sl'. 11.
mi
c.
WPVILLE THOXISON ox C~;ILTAIXPCHINODNRMI.
55
Hyocrinus bethelliaizus, sp. 11.
H . befhellianus ?
The last is a beautiful little thing which we dredged from a
depth of 2326 fathoms at Station 223, lat. 5” 31’ N., long.
145” 13’ E., in tlie east Pacific, with a bottom of Globigerinn-ooze,
and a bottom-temperature of 1O.2 C. It certainly is in many respectsvery unlike the adult H. fiethellialzus;but i t may possibly turn
out to be the young of that species. There was only one specimen.
It has been found impossible, or at all events too dangerous, to
evamine and compare the species belonging t o the Pentacrinidae
on board ; many of the specimens are very large, ?nd they are very
tender, requiring the utmost delicacy in handling ; it has therefore been thought in most cases advisable t o pack them away in
safety at once, and to defer their discrimination until our return
home.
‘ Challenger,’ South Atlantic,
March
M i ,
1876.
Notice of some Peculiarities in the Mode of Propagatioii of certaiu
Echinoderms of the Southern Sea. By Sir C. WYVILLE
THOMSON,
LL.D., D.Sc., F.R.S., B.L.S., F.G.S., &c., Regiuv
Professor of Pu’atnral Ristory in the University of Edinburgh,
Director of the Civilian Scientific Staff of the ‘ Challenger ’
Exploring Expedition.
[Read June 1,187G.l
THE very remarkable mode of reproduction of certain members of‘
all the recent classes of Echinodermata by the intervention of a
free-swimming bilaterally symmetrical ‘‘ pseudembryo ” developed
directly from the “ morula,” from which the true young is subsequently produced by a process of internal budding or rearrangeinent, has long been well known through the labours of a host of
observers headed and represented by the late illustrious Professor
Johannes Miiller of Berlin.
A t the same time it has all along been fully recognized that reproduction through the medium of a “ pseudembryo ” is not the
only method observed in the class, but that in several of the Echinoderm orders, while in a certain species a wonderfully perfect a i d
independent bilateral locomotive zooid may be produced, in verp
nearly allied species the youug Echinoderm may be developed iiii-