OE LITTLE-KNOWN COMATULJE. 493 



ward projections of the axillaries, wliich are roughly rhombic and 

 slightly wider than long. 



First brachials well separated laterally, with the inner sides 

 much shorter than the outer ones, and the distal edges much in- 

 cised to receive the strong backward projections of the quadrate 

 second brachials. The following joints have markedly unequal 

 sides with syzygies on the third or fourth, and again on the fifth, 

 sixth, or seventh brachials. 



Disk almost naked, 4 mm. diameter. Mouth excentric, and 

 surrounded by a large peristome, immediately behind which is 

 the nearly central anal tube. Brachial ambulacra close down 

 upon and between the muscular bundles. Skeleton light brownish 

 white. 



H.M.S. 'Challenger.' 1874. Station 174. Lat. 19° 10' S. ; Long. 178° 

 10' E. Depth 225, 610, and 210 fms. Globigerina-ooze. One specimen. 



Atelecrinus Wy villi differs from the two forms already described 

 in the greater squareness of the second radials, and in the curious 

 relation of the basals to the centrodorsal. They are of uniform 

 height, as in At. cuhensis, but are not in contact with the centro- 

 dorsal at the interradial angles of the calyx, being separated from 

 it on the exterior of the calyx by a gap which is filled up by peri- 

 some. Apart from its purely morphological importance, this 

 Pacific species is also interesting as showing the wide distribution 

 of the genus. 



EuJDiocRiNiJs, gen. nov. 



1868. Ophiocrinus, C. Semper, Wiegm. Archiv, Jahrg. xxxiv. p. 6S. 



1869. Comatula (Ophiocrinus), P. de Loriol, Denkschr. d. allg.schweiz. 

 Gesellsch. f. d. ges. Naturw. Bd. x.\iii. (Zurich, 1869), p. 57. 



1879. Ophiocrinus, P. H. Carpenter, Proc. Roy. Soc. No. 194, 1879, 

 p. 385. 



1879. Ophiocrinus, P. de Loriol, Monogr. des Crino'ides fossiles de la 

 Sm'sse (Geneva, 1877-79), p. 277- 



Centrodorsal and first radials like those of Antedon ; but the radials 

 bear the brachials directly without the intervention of axillaries, so that 

 there are only five undivided arms. Mouth central. Sacculi abundant; 

 scanty, or absent altogether. 



The genus Ophiocrinus was established by Prof. Semper in 

 1868 for an elegant little Comatula with five undivided rays, which 

 he had discovered in the Philippine Islands ; and in the follow- 

 ing year a fossil species was described by De Loriol from the 

 Neocomian of Switzerland. The generic value of the type was 



