REPORT ON THE CRINOIDEA. 315 
Proceedings of the Royal Society. It was not described, however, till the year 1872, 
when Sir Wyville contributed a notice of the “ Porcupine” Crinoids to the Royal Society 
of Edinburgh ; and in the following year he reproduced this description in The Depths 
of the Sea, together with a woodcut which gives a very fair idea of the principal char- 
acters of the type. All the entire specimens obtained were dredged at Station 17; but 
a few fragments of stem and arms were also met with at Station 174 (740 fathoms), . 
together with ten specimens of Antedon lusitanica. Thirty specimens were recently 
dredged by the “Talisman” in 1500 metres off Rochefort. Dr. Gywn Jeffreys’ records 
that “ portions of the arms occurred in several other of the ‘ Porcupine’ dredgings on 
the Lusitanian coasts; and joints of apparently the same species have been found 
by Prof. Seguenza in the Zanclean formation or older Pliocene near Messina.” The latter 
point, however, can hardly be properly decided without a careful study of both types. 
In the structure of the ray-divisions and arms, Pentacrinus wyville-thomsont is closely 
related to Pentacrinus miilleri, Pentacrinus maclearanus, and Pentacrinus altermcirrus, 
especially the latter; but it is at once distinguished from them all by the shape of the 
nodal joints, the short stout cirri which they bear, and the great length of the internodes 
which separate them. It is also remarkable for the manner in which the stem ends below 
in a nodal joint which is closed up beneath and rounded off, as shown in Pl. XXII. fig. 27. 
According to Sir Wyville Thomson? “all the stems of mature individuals of this species 
(which were dredged by the ‘ Porcupine’) end uniformly in a nodal joint, surrounded 
with its whorl of cirri, which curve downwards into a kind of grappling root (Pl. XIX. 
fig. 1). The lower surface of the terminal joint is in all smoothed and rounded, evidently 
by absorption, showing that the animal had for long been free” (Pl. XXIL fig. 27). The 
positions of this terminal nodal joint and the corresponding length of stem in three 
individuals which I have examined are as follows :—stem 80 mm. long, terminating at 
the fifth node ; stem 90 mm. long, terminating at the sixth node; stem 155 mm. long, 
terminating at the seventh node. 
The zoologists of the “Talisman” claim to have proved, however, that Sir Wyville 
Thomson was wrong in his belief that the individuals dredged by the “ Porcupine” were 
leading a semi-free existence, loosely rooted in the soft mud. In one of a series of 
popular articles by Mons. H. Filhol,’ a member of the “ Talisman” expedition, it is stated 
that Sir Wyville came to this conclusion after having examined one of the “ Porcupine” 
specimens ; and a free translation is given of the last sentence of the paragraph just 
quoted, from which, however, the words “in all” are entirely omitted. It is thus made 
to appear as if Sir Wyville had drawn his conclusions from the condition of only one 
example of Pentacrinus wyville-thomsoni, which is very far from being the case; while 
he also stated in the next paragraph to that quoted by Filhol that he had remarked 
1 Proc. Roy. Soc., 1870, vol. xix. p. 157. 
2 Proc. Roy. Soc. Edin., vol. vii. p. 767; The Depths of the Sea, p. 444. 
3 Explorations sous-marines, Voyage du “Talisman,” La Nature, No. 568, April 19, 1884. 
