352 BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



Specimens examined. — Eleven, from the following stations : 



Specimens of Pteraster jordani examined. 



Nature of bottom. 



3104. 

 334fi. 

 4354. 

 4405. 



Near Los Coronados Islands, Lower 



California. 



Off Santa Cruz Island, California 



on Sea Lion Rock, Washington 



Off naif Moon Bay, California 



Off Tillamook Bay, Oregon 



Near San Diego, California 



Between San Cleraente and Santa 



Catalina Islands, California. 

 Between Santa Catalina and Santa 



Barbara Islands, California. 



gray mud. 



gray sand, gravel.. 



green mud 



coral 



green mud 



V. S. Nat. Mus. 



A IhatTOSs, 1904. 



4415. 

 4421. 



.do. 



Between Santa Barbara and San 

 Nicholas Islands, California. 



Remnrlcs. — Pteraster jordani is a well-characterized species, having a rather 

 thin supradorsal membrane lacking calcareous deposits, but possessing faint muscle 

 bands connecting the two paxillar spines. The pedicels are very low and the spines 

 correspondingly long, being six or seven times the length of the former. Tube feet 

 are crowded in four rows, and the adambulacral combs have only three or four 

 slender spines, of which the inner is commonly shorter than the rest. From Pteraster 

 militaris the species is readily distinguishable by the absence of copious supradorsal 

 calcareous deposits, fewer adambulacral and mouth spines, fewer paxillar spines, 

 and in having four-ranked instead of two-ranked tube feet. 



Attention should be called to the fact that the individual dissected was a 

 male and that it was not different from the rest. The suggestion has been made" 

 that in the Pterasteridse the male may be some entirely different looking animal, 

 perhaps now described as a different species. Such is certainly not the case. 



PTERASTER MARSIPPUS Fisher. 



PL 100, fig. 1; pi. 101, fig. 2; pi. 115, fig. 4; pi. llfi, fig. 1. 

 Pteraster inarsippus Fisher, Ann. and Nat. Hist., ser. 8, vol. 5, Feb., 1910, p. 168. 



Diagnosis. — In general appearance and proportions similar to jordani; differs 

 in having three shorter paxillar spines; sparse calcareous deposits in the form of 

 simple straight rods of small size in supradorsal membrane; proximally five adam- 

 bulacral spines (far along ray only four) and especially in having the aperture 

 papilla partially tented over by a membrane passing from one comb to the next, 

 and mergmg outwardly with the actmolateral membrane. A shallow side pocket 

 is thus formed at the mouth of which is the aperture papilla. No spiracles. 

 Type, 11 = 100 mm.; 11 = 40 mm.; R = 2.5 r. Breadth of ray at base, 45 mm. R 

 varies to 1.8 r. 



o Lang, Text-book of Comp. Anat. (English translation), Pt. 2, 1896, p. 503. 



