A MONOGRAPH OF THE EXISTING CRINOIDS 397 



not been able satisfactorily to place Antedon finschii and A. erinacea because of a 

 lack of material for comparison. I remarked that the first (finschii) appears to be 

 most closely related to Pontiometra andersoni, and the diagnosis of the genus Pontio- 

 metra may have to be altered for its reception ; the second (erinacea) appears to repre- 

 sent a distinct generic type for which the name Oxymetra would be appropriate. 



In a paper published on April 17, 1909, I described a new species, Dichrometra 

 aranea, in the family Himerometridae. 



In a paper published on September 14, 1909, a new subfamily of the family 

 Himerometridae, the Stephanometrinae, was established, which included the genera 

 Oxymetra and Stephanometra; the genera Mariametra and Dichrometra were placed 

 in another new subfamily, the Mariametrinae. 



In 1911 I established the new genus Selenemetra in the subfamily Mariametrinae, 

 with Antedon finschii as the genotype. At the same time I described a new species 

 in this genus, S. viridis. 



In a paper on the crinoids of the Hamburg Museum published in 1912, after a 

 personal examination of Hartlaub's type specimen of Antedon erinacea, I said that 

 this species has nothing to do with the species of Stephanometra but is closely related 

 to the species that I had grouped in the genus Selenemetra, especially to S. tenuicirra. 

 Pointing out that the generic name Oxymetra with Antedon erinacea as the genotype 

 has precedence over Selenemetra with Antedon finschii as the genotype, I said that all 

 the species heretofore assigned to Selenemetra must be transferred to Oxymetra, of 

 which Selenemetra is a synonym. 



In my memoir on the crinoids of the Indian Ocean, published 13 days later than 

 the preceding paper, though written some time before it, I placed Oxymetra, with the 

 single species erinacea, in the family Stephanometridae, and Selenemetra, with the 

 species finschii, aranea, gracilipes, and viridis, in the family Mariametridae. 



In my revision of the family Mariametridae published in 1913 the genus Oxymetra 

 is given with Selenemetra as a synonym, and the species aranea, erinacea, finschii, 

 gracilipes, tenuicirra, and viridis are listed as belonging to it. 



In my report on the unstalked crinoids of the Siboga expedition I included a 

 key to the species of Oxymetra. The species recognized were tenuicirra, erinacea, 

 finschii (including gracilipes), and aranea (including viridis). 



KEY TO THE SPECIES IN THE GENUS OXYMETRA 



a 1 . Cirrus segments long, the longest about twice as long as broad and the distal about as long as 

 broad; 69-78 cirrus segments; 49 arms 150 mm. long (between Borneo and eastern Java; 

 82 meters) tenuicirra (p. 401) 



a 1 . Cirrus segments shorter, the longest but little longer than broad and the distal twice as broad 

 as long or even broader. 



6 1 . First four pairs of pinnules very stiff and spinelike; 36-51 (usually more than 40) arms 



90-115 mm. long; cirri with 48-63 (usually 50-60) segments (Philippines to Kei Islands, 

 and westward to Sunda Strait; 0-50 meters) erinacea (p. 398) 



6 2 . Proximal pinnules, though somewhat stiffened, are not spinelike, but become flexible distally 



and end in a delicate and more or less flagellate tip; 41-80 cirrus segments; 40-44 arms 

 90-140 mm. long (Philippines to New Britain and westward to northeastern Ceylon; 0-77 

 meters) finschii (p. 402) 



