REPORT ON THE CRINOIDEA. 243 



pniK'ipally of headless stems ul" Ba(/i//rrini(s (i/drichidims, suiiic witli ami smnc without 

 the basal ring at the .summit. 



■Mr. Murray tells me that one specimen of " Ptcmcj'invs" was presented to the 

 University Museum at Sydney ]>y Sir Wyville Thomson, whieh indicates that there must 

 have been several duplicates of the type. The only explanation of these focts which 1 

 can think of is, that Sir Wyville had not then (1874) made up his mind that the 

 relatively large individuals dredged at Stations 106, 14(), ami 147 were generically 

 identical with the small and immature specimen whieh lie had described two years 

 previously as the type of the new genus Bathycrinus ; so that he was led to give them the 

 MS. name Pterocriiuis, which he afterwards abandoned (1876) in favour oi Batlnjcriuus. 



Bailii/ci'iitus tjr((c(/is, Wyville Thomson, 1872 (PL Mlla. figs. 1-3; woodcut, fig. 16). 



1872. Bathyci'inus (jracillti, Wyv. Thorns., Proc. Vm\. Soc. Edin., vol. vii. p. 772; The Depth.s 

 ufthe Sea, pp. 450-454, tig. 73, 1873. 



Dimensions. 



Greatest lengtli of stem (about forty joints), . . . 57'00 mm.^ 



Longest stem-joints, ....... 2'50 ,, 



Length of head, ........ 8'00 ,, 



Description of an Individual. — Stem composed of about forty joints, of which the 

 first ten or twelve are \\dder than high, increasing in thickness from above downwards. 

 The following joints, at first cylindrical, increase rapidly in length, and acquire slightly 

 expanded ends, wdiicli become more and more marked in the lower joints, till the widtli 

 of the end is 1 mm., twice the width of the shaft. The joints diminish in length towards 

 the base of the stem, which ends in a small branching root. 



The basals are closely united into a smooth ring, the lower part of which is of the 

 same size as the upper stem-joints, but expands gradually upwards." The radial pentagon 

 aboA'e it expands more rapidly, so that there is a constriction at the basiradial suture, 

 though not so marked as in Baflnjcrinus cddriddanus. The radials are strongly convex 

 in the medio-dorsal line, but more flattened at the sides. Second radials nearlj' oblong, 

 with a sharp median ridge and a slight hollow on either side of it. Axillarics shorter 

 than the second radials and nearly oblong, and also marked 1)}' a sharp medio-dorsal 

 ridge which forks al)out the middle of the joint, and is continued on to the three lowest 

 brachials. There are only alxiut twelve brachials in the arm, all of which are distinctly 

 longer than wide, while the first two or three are scarcely wider than the rest, and have 

 straight lateral edges like the radials. The later joints overla}) rather sharply, so that 

 the dorsal edge of the arm is serrate. The disk is unprotected by plates. 



Colour, in spirit, brownish-white. 



Zoca?%.— H.M.S. " Porcupine," 1SG9. Station .37. Lat. 47' 38' N., long. 12° 8' W. ; 



1 Sir Wyville gave this measurement as 90 mm., which was possibly a misprint for (>(>. 

 -' This expansion is not quite marked enough in the figure. 



