64 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



of the crinoids of the British Museum published in 1913. It was inserted in the key 

 to the species of Cosmiometra in my memoir on the unstalked crinoids of the Siboga 

 expedition published in 1918 and the range and synonymy were given, and it was men- 

 tioned in my report on the crinoids of the John Murray Expedition to the Indian 

 Ocean, 1933-34, published in 1937. 



Genus PARAMETRA A. H. Clark 



Antedon (part) P. H. CARPENTER, Challenger Reports, Zool., vol. 26, pt. 60, 1888, p. 222, and following 

 authors. 



Charitometra (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 361. 



Thalassometra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 125. 



Paramclra A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (diagnosis; genotype Ante- 

 don orion A. H. Clark, 1907); Amer. Journ. Sci., ser. 4, vol. 32, 1911, p. 129 (characteristic of 

 the Japanese fauna; significance) ; Crinoids of the Indian Ocean, 1912, p. 9 (absent from Australia), 

 p. 10 (occurs in the Hawaiian Islands), p. 11 (absent from the west coast of the Malay Peninsula, 

 the Andamans, and farther west), p. 17 (significance of conditions in this genus in southern 

 Japan), p. 24 (range), p. 59 (in key), p. 213 (original reference; genotype); Die Crinoiden der 

 Antarktis, 1915, p. 125 (certain species of this genus show the characteristic features of Antho- 

 metra adriani). F. W. CLARKE and WHEELER, TJ. S. Geol. Surv. Prof. Pap. 90-L, 1915, p. 195 

 (inorganic constituents of the skeleton) ; U. S. Geol. Surv. Prof. Pap. 102, 1917, pp. 23 and following 

 (same). A. H. CLARK, Unstalked crinoids of the Stboja-Exped., 1918, pp. 146, 147, 148 (in key; 

 range), p. 158 (key to the included species). F. W. CLARKE and W. C. WHEELER, U. S. Geol. Surv. 

 Prof. Pap. 124, 1922, p. 20 (inorganic constituents of the skeleton). GISLEN, Ark. Zool., vol. 19, No. 

 32, Feb. 20, 1928, p. 8 (must be referred to the Charitometridae). A. H. CLARK, Journ. Linn. 

 Soc. (Zool.), vol. 36, No. 249, April 1929, p. 649. GISLEN, Kungl. Fysiograf. Siillsk. Handl., 

 new ser., vol. 45, No. 11, 1934, pp. 18, 20. 



Diagnosis. A genus of Thalassometridae in which the brachials beyond the basal 

 are more or less compressed laterally and carinate or subcarinate, or at least strongly 

 rounded dorsally; the division series, which are all 2, and arm bases are strongly rounded 

 dorsally, slightly or not at all flattened against their neighbors, the individual ossicles 

 plain, with everted edges, or with a more or less granular surface, usually with a delicate 

 middorsal carinate line; and the brachial carination is not produced into overlapping 

 spines. The 10-20 arms are 90-170 mm. long, and the short and rather stout cirri 

 are 20-28 mm. long with 18-27 segments. 



Geographical range. From southern Japan and the Hawaiian Islands to the Philip- 

 pines, the Moluccas, the Kei Islands, and Timor. 



Bathymetrical range.- From 128 to 795 meters. 



Thermal range. From 10.78 to 15.89 C. 



Remarks. The genus Parametra is related to Cosmiometra, but it represents a 

 more generalized type with the division series and brachials less specialized and the 

 cirri short and stout with relatively few segments. The species of Parametra, with their 

 short and stout cirri and the scarcely modified PI, bear a considerable superficial re- 

 semblance to certain species in the family Charitometridae, and they have been 

 erroneously referred to that family both by Gisl6n and by myself. 



The six species of Parametra fall into two groups. In the first and more typical 

 group, including compressa, granulata, orion, and lisa, the arms are carinate or sub- 

 carinate and PI resembles P 2 except for being longer and proportionately stouter. 

 The species of the other group, ajax and J?sAm, have the arms rounded dorsally and 

 PI more or less enlarged in the basal portion, thus forming to a certain extent a transition 



