744 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



c 1 . Cirri relatively long, the ratio of arm length to cirrus length being about 2. 5:1; only about 10 

 cirrus segments, which are very long, the longest up to six times as long as broad (Baffin Bay 



to Iceland; 2075-2623 meters)... septentrionalis (p. 752) 



c 2 . Cirri of moderate size, the arms 3-4 times as long; the longest cirri with 12-16 segments of 

 which the longest are rarely more than four times as long as broad. 



d 1 . PI with only about 11 segments (western Bering Sea; 3229 meters).. Jbrevicirra (p. 754) 



d 2 . PI with 15 or more segments. 



e 1 . Cirri XL LX (south of Sumbava, lesser Sunda Is. and from the Kei Islands; 385-959 



meters) thysbe (p. 755) 



e 2 . Cirri XXV-XXX. 

 /'. PI with about 20 segments (the Kermadec Islands and northeast of New Zealand; 1152- 



1279 meters) _.. alternata (p. 756) 



f 1 . PI with about 15 segments (southern Japan; 274-1417 meters) parva (p. 758) 



c 3 . Cirri relatively short, the arms at least five times as long; 16-20 segments in the longest, cirr 

 d 1 . P t the first genital pinnule; about 20 cirrus segments (southern Japan; 660-1186 meters). 



isis (p. 762) 



d 2 . P a the first genital pinnule; about 16 cirrus segments (northeastern Japan; 548-974 meters). 



comaster (p. 763) 



THAUMATOMETRA TENUIS (A. H. Clark) 



FIGURE 47 

 [See also vol. 1, pt. 1, figs. 30 (p. 71), 298 (p. 264), 510 (p. 373); pt. 2, figs. 108-111 (p. 67), 128 (p. 79)] 



tAntedon, sp. VON GRAFF, Challenger Reports, Zoology, vol. 10, No. 27, 1884, p. 79 (Vladivostok; 

 myzostomes). 



Antedon tennis A. H. CLARK, Proc. U.S. Nat. Mus., vol. 33, 1907, p. 80 (description; Albatross station 

 4997); Proc. Biol. Soc. Washington, vol. 21, 1908, p. 127 ( = A. ciliala, the type species of 

 Thaumatomelra) . SOWBRBT, The naturalist in Manchuria, Tientsin, vol. 5, 1930, p. 79. 



Antedon ciliala A. H. CLARK, Proc. U.S. Nat. Mus., vol. 33, 1907, p. 81 (description; Albatross station 

 4982); Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (listed). SOWERBY, The naturalist 

 in Manchuria, Tientsin, vol. 5, 1930, p. 79. 



Antedon stella A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (new name for 

 Anledon tennis A. H. Clark, 1907, not of P. H. Carpenter, 1887); Proc. U.S. Nat. Mus., vol. 34, 

 1908, p. 495 (Antedon tennis P. H. Carpenter a nomen nudum so that it does not invalidate 

 Antedon tenuis A. H. Clark). 



Thaumatomelra tenuis A. H. CLARK, Proc. U.S. Nat. Mus., vol. 34, 1908, p. 275, fig. 4 (centrodorsal 

 and base of a post-radial series); vol. 35, 1908, p. 117, fig. 11 (arm structure); Vid. Medd. Nat. 

 Foren. K0benhavn, 1909, p. 191 (synonymy, includes ciliata; new localities) ; Crinoids of the 

 Indian Ocean, 1912, p. 245 (synonymy; range); Proc. Biol. Soc. Washington, vol. 26, 1913, p. 182 

 (new locality); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 65 (comparison with T. abys- 

 sorum); Journ. Washington Acad. Sci., vol. 5, 1915, No. 3, p. 80 (range and its significance); 

 No. 6, p. 213 (faunal relationships; origin), p. 215 (faunal affinities; range); Unstalked crinoids 

 of the Siboga-Exped., 1918, p. 254 (in key; range), p. 256 (references). GISLEN, Vid. Medd. 

 Nat. Foren. K0benhavn, vol. 83, 1927, p. 52 (Mortensen's specimen probably the young of this 

 species). A. H. CLARK, Explorations des mers de 1'U.R.S.S., vol. 23, 1937, p. 221 (localities old 

 and new; range), p. 222 (association) (in Russian), pp. 228-230 (in English version). DJAKONOV, 

 Bull. Pacific Inst. Fish. Oceanogr., Vladivostok, vol. 30, 1949, p. 13 (in key). 



maumatometra cf. tennis GISLEN, Vid. Medd. Nat. Foren. K0benhavn, vol. 83, 1927, p. 3 (sta. 20; 

 108 meters), pp. 51-52 (description), p. 69 (listed); fig. 41, p. 44. 



Thoumatometra tenuis A. H. CLARK, Explorations des mers de 1'U.R.S.S., vol. 23, 1937, p. 229. 



Diagnostic features . The large size of this species, which has an arm length of up 

 to 130 mm., together with the form of PI, composed of about 35 segments, of which the 

 proximal 12 are short, and P 2 , which is nearly as long, but with only about 20 mostly 

 elongated segments, serve to distinguish tenuis at once from the other species of the genus. 



