EASTERN TROPICAL TACIFIC ASTEROIDEA. 95 



soceufaius Fisher, 1905. Ibid., p. ilQ. Monterey Bay, Cala., 916 fms. See Myxoderma. 



evermanni Fisher, 1905. Ibi<l., p. 317. Hetwcen San Diepo amrSaii Cleinentc Island, Cala., 500-507 



fnis. 

 magiiificiis lAJiiwui, 1905. Mem. M. (". Z., 32, p. 159. (!ulf of Panama, 1,071 fms. 

 7iudus Lttdwig, 1905. Ibid., p. 164. Gulf of California, 998 fm.s. 

 hirsutus Lvvwig, 1905. Ibid., p. 172. South of Acapulco, Mexico, 1,878 fms. 

 longispiniis Ludwig, 1905. Ibid., p. 180. Eastern Tropical Pacific, 780-1,320 fms. 

 spimdo.-itts Fisher, 1906. Bull. U. S. Fish Comm., 1903, p. 1102. Hawaiian Islands, 328-557 fms. 

 bispinosits Koehlek, 1909. I'rincesse-Alice Ech., p. 316. No locality given. 

 addini KoEiiLER, 1909. Investigator Deep Sea Ast., p. 108. Bay of Bengal, 5()9 fms. 

 pldlyacanlhiis H. L. Cl.vrk, 1913. Bull. Amer. Mus. Nat. Hist., 32, p. 199. OIT west coast of Lower 



California, 284 fms. 

 ophiaclis Fisher, 1916. Proc. Biol. Soc. Wash., 29, p. 29. Gulf of Tomini, Celebes, 834 fms. 

 microporus Fisher, 1916. Ibid., p. 30. Southwest of Amblan Island, Moluccas, 700 fms. 

 carinatus pkilippinensis Fisher, 1916. Ibid., p. 30. Sibuko Bay, Borneo, 415 fms. 

 macracantha H. L. Clark, 1916. Endeavour Ech., p. 68. Great Australian Bight, 250-450 fms. 

 aclinocles Fisher, 1919. Ann. Mag. Nat. Hist., ser. 9, 3, p. 390. Aleutian Islands, 1,217 fms. 

 evermanni inordax Fisher, 1919. Ibid., p. 390. Off Washington, 477 fms. 



Of the above species, tenuis and longispinus are based on very young speci- 

 mens, in which the real specific characters are as yet undeveloped. It is useless 

 to attempt to compare them with the adults of other species and they are there- 

 fore omitted from the keys. Until adults are collected, accompanied by young 

 and intermediate stages, these two names are of Uttle service. Ludwig (1905. 

 Mem. M. C. Z., 32, p. 177) has described another young Zoroaster but he re- 

 frained from giving it a name. Koehler's record (1908. Scotia Ech., p. 566) of 

 tenuis from 1,742 fms. in the extreme South Atlantic Ocean merely shows that 

 the genus ranges that far south. It is highly improbable that his specimen is 

 conspecific with Sladen's type of tenuis. Of course, bispinosus is only a slip 

 of the pen for trispinosus. 



The remaining twenty-nine species include several groups which seem to be 

 worthy of rank as distinct genera. First of these is Mammaster, proposed by 

 Perrier in 1894 (Travailleur and Tahsman Stell., p. 125) with Z. sigsbeei as the 

 type. There is Uttle doubt that the genus is very nearly related to Cnemidaster 

 as that group now stands, thanks to Fisher's investigations (1919. BuU. 100 U. S. 

 N. M., p. 480^84). But I do not tliink it will ever be necessary "to merge 

 the two genera" as Fisher suggests. Foi there is a rather striking character,' 

 hitherto apparently overlooked, which distinguishes Mammaster at once from 

 any of the known species of Cnemidaster. This is given below in the key to 

 genera and while it may not be of great morphological importance, it affects 

 very evidently the general appearance of the disk. The Albatross collections 

 in the Phihppines have revealed so well the growth-stages of Cnemidaster that 

 we can now deUmit that group of East Indian and Pacific species very well. 



