PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 603 



but tapers more gradually and evenly so that it appears stouter in the proximal half. 

 It bears a gonad, which extends from the middle of the fourth to the end of the proximal 

 third of the sixth segment. The next three pinnules are similar to P 3 . The distal 

 pinnules are 6 mm. long, with 17 segments which, except for the first two, are much 

 elongated and very slender. 



At the tune Psathyrometra acuta was described, its relationship with my earlier 

 Adelometra tenuipes and to Hartlaub's Antedon arcana was completely overlooked. I 

 remarked that no species of the genus Psathyrometra had heretofore been known from 

 the Atlantic though it is represented in the Indian and Pacific Oceans by 14 species, 

 including one from Panama and the Galapagos Islands. I said that P. acuta appears to 

 be most closely related to P. major and P. mira, which are found on the western coast of 

 the Malay Peninsula and southward to the Lesser Sunda Islands in from 185 to 434 

 fathoms of water. 



Localities. Albatross station 2348; off Havana, Cuba (lat. 2310'39" N., long. 

 8220'21" W.); 386 meters; coral; January 20, 1885 [A. H. Clark, 1908, 1923, 1936, 

 1940] (1, the holotype, U.S.N.M., 22677). Type locality. 



Caroline station 102; northeast of Puerto Rico (lat. 1851' N., long. 6432' W.); 

 165-914 meters; March 4, 1933 [A. H. Clark, 1934, 1940] (3, U.S.N.M., E.3121 [type of 

 Psathyrometra acuta], E.3122, E.3123). 



No locality; Blake [Hartlaub, 1912; A. H. Clark, 1923, 1940] (1, type of Antedon 

 arcana, 7M.C.Z.). 



History. Under the name of Adelometra tenuipes this species was very inadequately 

 described in 1908 from a specimen from Albatross station 234S. In 1912 Dr. Clemens 

 Hartlaub described and figured a specimen without locality from the Blake collection 

 under the name of Antedon arcana. He sent me a proof of his lithographic plate, which 

 had originally been prepared by Carpenter, and I agreed with him that figures 2 and 6 

 probably were cirri from the specimen shown in figure 1. But I entirely failed to 

 associate Antedon arcana with my Adelometra tenuipes. In 1923 in a list of the crinoids 

 of the Atlantic basin I included Adelometra tenuipes and Coccometra arcana, with the 

 localities. At that time I placed more reliance on the short segments of P : shown in 

 Hartlaub's figure than on the characters of the centrodorsal. In 1934 I described 

 Psathyrometra acuta, which had been dredged by the yacht Caroline of the Johnson- 

 Smithsonian Deep-Sea Expedition at station 102, failing to notice its relationship with 

 Adelometra tenuipes and Antedon arcana. In 1936 Adelometra tenuipes was made the 

 type of the new genus Caryometra. 



In a revision of the species of the family Antedonidae occurring in the west tropical 

 Atlantic published in 1940 Antedon [Coccometra] arcana, and Psathyrometra acuta were 

 placed in the synonymy of Caryometra tenuipes, though without any explanation. 



CARYOMETRA LISA A. H. Clark 



Caryometra lisa A. II. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 14, No. 2, 1940, p. 142 (in key), p. 



154 (description; Atlantis station 2990), pi. 21, fig. 6; text fig. 5, p. 156. H. L. CLARK, Mem. Soc. 



Cubana Hist. Nat., vol. 15, No. 1, 1941, p. 12 (Atlantis station 2990; notes), p. 13 (taken with 



Atelecrinus balanoides). A. H. CLARK, Bull. U.S. Fish. Cbmm., vol. 55, 1954, p. 374 (listed). 

 Caryiometra lisa A. H. CLARK, Mem. Soc. Cubana Hist. Nat., vol. 14, No. 2, 1940, p. 156, legend for 



fig. 5. 



Diagnostic features. The cirri are long and very slender, with 17 to 28 (usually 

 20 to 25) segments, of which the longest proximal are about five times as long as broad 



556-62267 40 



