282 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



TAntedon marmorata (Vienna Mus., MS.) P. H. CARPENTER, Challenger Reports, Zoology, vol. 26, 

 pt. 60, 1888, p. 202 (Norfolk Island; nomen nudum). 



Tropiometra carinata (part) A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 34.9 (in- 

 cluded under this name up to 1911); Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 182 

 (East Indies; characters). 



Tropiometra sp. A. H. CLARK, Amer. Nat., vol. 42, No. 500, 1908, p. 541 (known only from the 

 Indo-Pacific-Japanese area); Notes Leyden Mus., vol. 33, 1911, p. 189 (Indian Ocean). 



Antedon encrinus (Lutken, MS.) A. H. CLARK, Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 117 

 (synonym of T. carinata). 



Alecto encrinus (Lutken, MS.) A. H. CLARK, Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 182 

 (in synonymy of Tropiometra carinata) ; Proc. U. S. Nat. Mus., vol. 40, 1911, p. 36 (in synonymy 

 of Tropiometra encrinus); Crinoids of the Indian Ocean, 1912, p. 177 (same). 



Tropiometra encrinus A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 36 (in part; east coast of 

 Asia); Notes Leyden Mus., vol. 33, 1911, p. 189 (companion with Tropiometra, sp., from the 

 Indian Ocean); Die Fauna Siidwest-Australiens, vol. 3, Lief. 13, 1911, p. 440 (East Indian 

 species); Mem. Australian Mus., vol. 4, 1911, p. 722 (range in Australia unknown), p. 735 

 (in key), p. 780 (no definite Australian records; Norfolk Island); Rec. Indian Mus., vol. 7, pt. 3, 

 1912, No. 26, p. 270 (Sadras [= Madras]); Smithsonian Misc. Coll., vol. 60, No. 10, 1912, p. 29 

 (Java; specimen not seen); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 384 (identity), p. 402 (com- 

 parisons with related species; eastern Asia; Indian Ocean; ?India; descriptions); Crinoids of the 

 Indian Ocean, 1912, p. 177 (in part; east coast of Asia; Java), fig. 29, p. 178 (type specimen); 

 Proc. Biol. Soc. Washington, vol. 26, 1913, p. 179 (range in eastern Asia) ; Beitrage zur Kenntnis 

 der Meeresfauna Westafrikas, Echinod. II, Crinoidea, 1914, p. 313 (range; ?India; East Indies; 

 eastern Asia) ; Journ. Washington Acad. Sci., vol. 5, No. 6, 1915, p. 214 (Malayan species; range and 

 its significance). H. L. CLARK, Spolia Zeylanica, vol. 10, pt. 37, 1915, p. 85 (Ceylon; 2 charac- 

 teristic specimens), p. 93 (occurs at Ceylon). A. H. CLARK, Unstalked crinoids of the Siboga- 

 Exped., 1918, p. 131 (in key; range). GISLEN, Ark. Zool., vol. 19, No. 32, 1928, p. 6 (little 

 different from T. picta). A. H. CLARK, Rec. Indian Mus., vol. 34, pt. 4, 1932, p. 560 (Pamban 

 Beach; near Mandapam; Madras; Waltair; detailed description and notes), pi. 19, figs. 10-12; 

 pi. 20, figs. 13-17. GISLEN, Vid. Medd. Dansk. Naturh. Foren. K0benhavn, vol. 93, 1933, p. 478 

 (validity), fig. 4, p. 477 (figure of cirrus). 



Tropiometra clarki GISLEN, Kungl. Svenska Vet.-Akad. Handl., ser. 3, vol. 17, No. 2, 1938, p. 4 

 (listed), p. 16 (new name for the form represented by the specimen from Mandapam described 

 in detail in Clark, 1932, p. 561). 



Diagnostic features. The carination of the arms is slight in the proximal half, 

 and entirely absent or only very faintly indicated in the distal half; the cirri are 

 rather large, XX-XXXIII (usually about XXV), 19-34 (averaging 25), from 20 to 35 

 (averaging 24) mm. long; the arms are up to 180 mm. in length, though rarely 

 exceeding 150 mm. 



Description. The centrodorsal is a thin to rather thick disk with the broad 

 dorsal pole 5-6 mm. in diameter, flat or slightly concave, more or less marked with 

 faint radiating lines, and toward the periphery raised at the bases of the larger cirri., 

 The cirri are arranged in one and a partial second, two, or two and a partial third 

 marginal rows. 



The cirri are XXV, 29-34 (usually 32-33), from 30 to 35 mm. long. The first 

 segment is very short, commonly a thin disk from six to eight tunes as broad as long, 

 and the second is between two and two and one-half times as broad as long. The 

 segments following may remain subequal, between half again and twice as broad as 

 long, or they may become somewhat longer on the fifth-ninth or sixth-tenth, and 

 shorter again in the distal half of the cirri. The distal edge of the cirrus segments in 

 lateral view is very strongly sinuous. The cirri may remain uniform in width, as 



