78 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Analcidometra A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 10 (women nudum; represents in 

 the West Indies the East Indian Stephanometra) ; Mem. Australian Mus., vol. 4, 1911, p. 769 

 (represents Stephanometra in the Caribbean Sea), p. 779 (used with the specific name caribbea 

 [Oligometra caribbea A. H. Clark, 1908]); Crinoids of the Indian Ocean, 1912, p. 13 (corresponds 

 to the East Indian Stephanometra'}, p. 22 (represents the Stephanometridae in the West Indies; 

 first confused with Oligometra and the Caribbean species described as 0. caribbea) ; Internat. 

 Rev. gesamt. Hydrobiol. und Hydrogr., 1914, p. 4 and following (represents Oligometrides in 

 the Atlantic; range and its significance); Beitrage zur Kenntnis der Meeresfauna Westafrikas, 

 Echinod. II, Crinoidea, 1914, p. 309 (Caribbean; corresponds to Oligometrides'); Journ. Wash- 

 ington Acad. Sci., vol. 5, No. 1, 1915, p. 8 (most closely related to the Australian Oligometrides; 

 does not occur on the eastern shores of the Atlantic) ; Die Crinoiden der Antarktis, 1915, p. 181 

 (range; represented in the Indo-Pacific by Oligometrides'); Journ. Washington Acad. Sci., vol. 6, 

 No. 5, 1916, p. 115 (most closely related to Austrometra and to Oligometrides) ; Unstalked crinoids 

 of the Sz&o^a-Exped., 1918, p. Ill (in key); Univ. Iowa Studies Nat. Hist., vol. 9, No. 5, 1921, 

 p. 12 (confined to the West Indies), p. 18 (in key); The Danish Ingolf-Exped., vol. 4, No. 5, 

 Crinoidea, 1923, p. 39 (range). GisLlsN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, 

 No. 11, 1934, p. 18. 



Diagnosis. A. genus of Colobometridae including small species with 10 arms 

 15-60 mm. long in which the third-fifth segments of the genital pinnules are broad- 

 ened to protect the gonads; either PI or P 2 is the longest and stoutest pinnule; the 

 short and stout cirri are composed of 15-23 segments of which those in the outer half 

 bear dorsally a prominent median spine which at first is flanked on either side by a 

 much smaller spine, but later stands alone. 



Geographical range. From the Florida Straits and the Bahamas to Barbados 

 and Colon. 



Bathymetrical range. From 5.5 to 64 meters. 



Remarks. This genus is closely related to Austrometra, differing from it most 

 obviously in having the distal cirrus segments with a prominent median dorsal spine. 

 In Cotylometra the outer cirrus segments also have a single median spine, but in that 

 genus the cirri are longer and more slender with more than 24 segments, and the 

 segments of the genital pinnules are not expanded. 



History. The first known species of this genus was described under the name of 

 Antedon armata by Count Pourtales in 1869. Dr. P. H. Carpenter in 1888 referred 

 armata to the Tenella group of Antedon. 



In 1908 hi a list of species assigned to my new genus Oligometra there appears as a 

 nomen nudum the name Oligometra caribbea; this species was, however, described in 

 the following month. 



Inalistof West Indian and corresponding East Indian comatulid genera published 

 by me early in 1911 the generic name Analcidometra appears as a West Indian type 

 corresponding to the East Indian Stephanometra. Later in the same year in my memoir 

 on the crinoids of Australia I said that Stephanometra is represented in the Caribbean 

 Sea by Analcidometra, and later used the combination Analcidometra caribbea, in a 

 footnote identifying the species as Oligometra caribbea A. H. Clark, 1908. In my 

 memoir on the crinoids of the Indian Ocean published in 1912 I said that the East 

 Indian genus Stephanometra corresponds to the West Indian Analcidometra, which 

 represents the family Stephanometridae (now merged with the Mariametridae) in the 

 western Atlantic. I remarked that Analcidometra is a curious type and was first 

 confused with the genus Oligometra. The reason for erroneously referring Anal- 

 cidometra to the family Stephanometridae was that at that time the transverse ridge 



