140 NATURAL HISTORY BULLETIN 



in Pontaster, if the character of the pedicellariae be ignored, for 

 in the type of the latter the pedicellarige are bivalved. Moreover, 

 in typical Font aster the papularia are more swollen and have a 

 specialized calcareous framework internally. 



The type was from station 231, off St. Vincent, in 95 fathoms 

 (six specimens). The specimens from this locality, in the Blake 

 collection, I have seen. They are all young except one. 



Pectinaster mixtus Yerrill, sp. nov. 



Cheiraster trtirabilis (pars) Perrier, op. cit., 1884 (non 1881), p. 256, pi. 

 viii, figs. 7, 8; op. cit., p. 276c, pi. xx, fig. 4, 1894. 



Plate yi ; figure 2. Plate xv ; figure 2. Plate xvii ; figure 1. 



It seems necessary, or at least desirable, to have a special name 

 for the very common and often abundant small form of this 

 group found in the West Indies. It is probably more abundant 

 and more widely diffused than any other starfish of that region, 

 in moderate depths. It also has a considerable range in depth. 



At present it is impossible to tell whether any of the specimens 

 ai^e mature. Most are e\ddently immature, but cannot be re- 

 ferred to either of the larger species mth certainty. Certainly 

 they are not all of one species, as first described. Large num- 

 bers of specimens have been grouped together by Perrier (as his 

 C. mirahilis of 1894, not of 1881). I have examined a consid- 

 erable number of his lots, biit not all, and have found some evi- 

 dently mixed lots, including, for instance, the young of C. echin- 

 ulatus. Others might be the young of C. planus or P. vincenti. 

 Still, most of them appear to belong together. I propose to call 

 the more common species, provisionally at least, C. mixtus = C. 

 mirahilis Per., 1894, in part. Although the specimens are prob- 

 ably all immature I am unable to refer them to either of the 

 larger species described. 



A specimen that agrees very closely with the one described 

 by Perrier comes from Albatross station 2341, off West Florida, 

 in 143 fathoms (No. 10,226, Nat. Mus.). This may be taken as 

 the type. (See plate vi, figure 2.) 



It has the radii 6°^^ and 26°^™ ; marginal plates 22. The dorsal 

 plates are nearly flat, polygonal, closely packed or tesselated, un- 

 equal in size. They bear numerous minute, almost granule-like 



