278 BULLETIN OF THE 



test, subject to the greatest variation in Spatangoids. These consist in the 

 greater prominence of the posterior abactinal interambulacral ridge ; the 

 anal opening is almost circular, and covered by a larger number of plates 

 than in the European species, where they are larger and few in number. 

 The extremity of the subanal plastron also projects beak-like, and is more 

 prominent, though not as much as in E. lievigaster. 

 Littoral, to 8j fathoms. 



Schizaster cubensis D'Oru., Agass. Cat. Rais. 



Fragments of a true Schizaster, allied to S. gibbcrulus,were collected. 

 These are referred with same doubt to the above species ; especially if the 

 determination of Dujardin is correct, who refers it to Periaster, and must 

 have had access to the original specimen. The fragments have, however, 

 the distinctive mark, given in the Catalogue Raisonne, of having the anterior 

 ambulacrum much less sunken than in S. canuliferus, — a character which 

 has nothing to do with Periaster. 



Fragments from 80 fathoms. 



Moera atropos Mich., Rev. Mag. de Zool. 



Syn. Schizaster atropos Ac, Agass. Cat. Rais. 

 Schizaster lachesis Gir., Proc. B. S., 1850. 

 Moera lachesis Des., Synops. 

 Mcera atropos Lutk., Bidrag. 



Fragments of this species were dredged from a depth of 80 fathoms. 

 Girard has attempted to separate specimens from Texas, of slightly more 

 elongated outline, as a distinct species. The color of M. atropos when alive is 

 yellowish. The spines, where more thickly clustered, are brownish ; they are 

 short except where they cover the sunken ambulacra, which are entirely hid- 

 den by the spines meeting from both sides. On the lower surface, the inter- 

 ambulacral plastron is covered by long spines, which as they wear out at the 

 extremity become spatula-shaped. On the side of the ambitus, and the upper 

 lateral part of the posterior ambulacra, the spines attain a great length, es- 

 pecially towards the mouth, where they are most closely crowded together. 

 Gray is particularly unfortunate in his subdivision of this genus; he has, 

 like Michelin, divide: 1 Schizaster, but into three genera (following exactly 

 the three typ ss of the Cat. Rais.). "Nina" having for its type S. canalife- 

 rus, while S. gibberulus, which is most closely allied to it and cannot be sep- 

 arated generically, figures as Brisaster, and the most abnormal of the Schi- 

 zasterida* is retained as Schizaster. Michelin's subdivisions, made at the 

 same time, have been adopted here. 



The attempts made thus far to restore old generic names, in vogue before 



