EASTERN TROPICAL PACIFIC ASTEROIDEA. 87 



Pterasteridae. 



Although there are only two specimens of this family in the collection, 

 their identification has necessitated a critical revision of the genus Hymenaster 

 and it has seemed worth while to publish this revision. The first reference to 

 the gi-ouii in literature occurs in Wyville Thomson's The Depths of the Sea, 

 pubhshed in 1873, but it was really the work of the Challenger, in the same 

 and three subsequent years, which revealed what a wide-spread and character- 

 istic deep-sea genus Hymenaster is. Since that day numerous additional spe- 

 cies have been taken, until the number wliich have been named now reaches a 

 total of forty-four. The following list gives these species in their chronological 

 order with the necessary bibliographical references and the locality and depth 

 at which they were first taken. 



List of the speciiic names used with Hymenaster. 



pellucidus Wtville Thomson, 1873. Depths of the Sea, p. 120. Faeroe Channel, 580 fms. 



nobilis Wtville Thomson, 1876. Journ. Linn. See. Zool., 13, p. 73. 1,099 miles southwest of Australia, 



1,800 fms. 

 memhranaceus Wyville Thom.son, 1877. The Atlantic, 1, p. 108.' Off Portugal, 1,12.5 fms. 

 formosus Slauen, 1882. Journ. Linn. Sec. ZooL, 16, p. 213. 1,099 miles southwest of Austraha, 1,800 



fms. 

 pergamentaceus Sladen, 1882. Ibid., p. 215. East of Buenos Ayres, 2,650 fms. 

 sacculatus Sladen, 1882. Ibid., p. 217. 1,099 miles southwest of Austraha, 1,800 fms. 

 eckinulatm Sladen, 1882. Ibid., p. 218. Mid-South Pacific, 2,335 fms. 

 camosus Sladen, 1882. Ibid., p. 220. Off Chili, 1,500 fms. 

 glaums Sladen, 1882. Ibid., p. 221. Southwest of Suruga Gulf, Japan, 565 fms. 

 I'icariiis Sladen, 1882. Ibid., p. 223. Between Juan Fernandez and Valparaiso, 1,375 fms. 

 infernalis Sladen, 1882. Ibid., p. 224. Mid-North Pacific, 2,900 fms. 

 caelatus Sladen, 1882. Ibid., p. 225. 1,099 miles southwest of Australia, 1,800 fms. 

 crucifer Sladen, 1882. Ibid., p. 227. 1,099 miles southwest of Austraha, 1,800 fms. 

 anomalus Sladen, 1882. Ibid., p. 228. North of Tristan da Cunha, 1,425 fms. 

 latebrosus Sladen, 1882. Ibid., p. 230. Southwest of Austraha, 1,950 fms. 



porosissimus Sladen, 1882. Ibid., p. 231. Between Juan Fernandez and Valparaiso, 1,375 fms. 

 graniferus Sladen, 1882. Ibid., p. 233. Between Marion and Crozet Islands, 1,375 fms. 

 geometricus Sladen, 1882. Ibid., p. 234. Mid-South Pacific, 2,335 fms. 

 pullalv^ Sladen, 1882. Ibid., p. 235. Southwest of Admiralty Islands, 1,070 fms. 

 coccinatus Sladen, 1882. Ibid., p. 238. Between Marion and Crozet Islands, 1,375 fms. 

 pratcoquis Sl.\den, 1882. Ibid., p. 240.= Near Crozet Islands, 1,375-1,600 fms. 

 modestus Vekrill, 1885. Amer. Journ. Sci. ser. 3, 29, p. 151.^. Off southern New England, 1,098-1,451 



fms. 



' It is perhaps debatable whether there is an adequate description in connection with this first use 

 of the name, but as the points mentioned would probably distinguish the species from the only other 

 Hj-menasters known at the time, it may be just as weU to let the name continue to rest on WyviUe 

 Thomson's authority. 



2 These eighteen species described by Sladen, as well as the three named by Wy\'Llle Thomson, are 

 fully iOustrated in Sladen's Challenger Asteroidea, issued in 1889. 



^ It is doubtful whether this description is adequate. A much better one appeared in 1894, Proc. 

 U. S. N. M., 17, p. 277. 



