REPORT ON THE CRINOIDEA. 315 



Proceedings of the Royal Society. It was not described, however, till the year 1872, 

 when Sir Wy^dlle 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 princij)al 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 17a (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-thomsoni is closely 

 related to Pentacrinus miilleri, Pentacrinus maclearanus, and Pentacrimis alter nicirr us, 

 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 grap^iling root (PI. XIX. 

 fig. 1). The lower surface of the terminal joint is in aU smoothed and rounded, evidently 

 by absorption, showdng that the animal had for long been free " (PL XXII. 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 W}mlle 

 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 AVyville 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- Wy\Tlle had drawn his conclusions from the condition of only one 

 example of Pentacrinus uyville-thomsoni, which is very far from being the case ; while 

 he also stated in the next paragraph to that cjuoted by Filhol that he had remarked 



' Proc. Roy. Soc, 1870, vol. xix. p. 157. 



2 Proc. Boy. Soc. Edin., vol. vii. p. 767 ; The Depths of the Sea, p. 444. 



3 Explorations sous-mai-iiies. Voyage tlu " Talisman," La Nature, No. 568, April 19, 1884. 



