396 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



P. Lateral portions of dorsal surface of division series with closely crowded small spines, 

 tubercles, or granulations (southern Japan from Oki Islands in Sea of Japan to 

 Tokyo Bay, and southward to Amboina, Kei Islands, Timor, Flores, and Sapeh 

 Strait, and westward to Mergui Archipelago; 40-153 meters) Mariametra (p. 566) 



Genus OXYMETRA A. H. Clark 



Antedon (part) HARTLAUB, Nachr. Ges. Gottingen, May 1890, p. 176, and following authors. 



Himerometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, 1907, p. 356. 



Dichrometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, pp. 13, 76. 



Oxymetra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 13 (characters; genotype 

 Antedon erinacea Hartlaub, 1890), p. 176 (referred to the Stephanometrinae) ; Mem. Australian 

 Mus., vol. 4, pt. 15, 1911, p. 725 (absent from Australia); Smithsonian Misc. Coll., vol. 60, No. 

 10, 1912, p. 22 (includes Selenemetra) ; Crinoids of the Indian Ocean, 1912, p. 57 (in key), p. 131 

 (original reference; type); Proc. Biol. Soc. Washington, vol. 26, 1913, p. 141 (includes Selene- 

 metra; referred to the Mariametridae), p. 143 (synonymy; genotype; range, depth; included 

 species), p. 142 (in key); Unstalked crinoids of the Siboga-Exped., 1918, p. 97 (in key; range), 

 p. 98 (key to the included species). 



Selenemetra A. H. CLARK, Proc. TJ. S. Nat. Mus., vol. 39, 1911, p. 541 (diagnosis; genotype Antedon 

 finschii Hartlaub, 1890; referred to the Mariametrinae) ; Memoirs of the Australian Mus., vol. 4, 

 pt. 15, 1911, p. 725 (absent from Australia); Smithsonian Misc. Coll., vol. 60, No. 10, 1912, 

 p. 22 (synonym of Oxymetra); Crinoids of the Indian Ocean, 1912, p. 9 (absent from Australia), 

 p. 10 (absent from Japan; reason), p. 11 (represented in Ceylon region), p. 22 (distiibution in 

 detail), p. 57 (in key), p. 139 (original reference; type); Proc. Biol. Soc. Washington, vol. 26, 

 1913, p. 141 (synonym of Oxymetra). 



Diagnosis. A genus of Mariametridae in which the cirri are long and stout with 

 more than 40 (rarely less than 50) segments, of which the distal bear dorsal spines; 

 several pairs of the proximal pinnules are moderately enlarged and moderately elon- 

 gated, and more or less stiffened, at least in the basal half; and the arms are 40 or more 

 in number. 



Geographical range. From the Philippine Islands southward to New Britain and 

 the Kei Islands and westward to Ceylon. 



Bathymetrical range. From the shoreline down to 82 meters. 



Remarks. The genus Oxymetra as herein understood includes three closely 

 related species that may eventually prove to be simply more or less distinct forms 

 of the same species. 



Although Oxymetra erinacea with its stiff, enlarged, and spinelike proximal pinnules 

 seems at first sight to be very different from 0. finschii with its more slender proximal 

 pinnules of which more or less of the distal portion is flexible, this difference is really 

 of little importance, for in many single species in genera of the Zygometridae, 

 Himerometiidae, Mariametridae, and Colobometridae the proximal pinnules vary 

 greatly in length and stiffness. Oxymetra tenuicirra is simply a form of 0. erinacea 

 with elongated cirrus segments. 



History. The two first-known species of this genus, finschii and erinacea, were 

 described by Dr. Clemens Hartlaub in the genus Antedon in 1890. 



When the new genus Himerometra was established by me in 1907 both of these 

 species were included in it. In 1908 I described a new species under the name of 

 Himerometra gracilipes (=finschii). 



In the revision of the family Himerometridae published on January 9, 1909, 

 I referred Himerometra gracilipes to the new genus Dichrometra. I said that I had 



