356 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



o'. Dorsal processes on the outer cirrus segments consisting of a median keel only; not more than 

 30 arms. 

 6'. Arms 30 in number; midventral line of the cirri sharp (Philippine Islands; 89 meters). 



acanthaster (p. 363) 

 ¥. Arms 20 or fewer; cirri ventrally rounded. 



c'. Cirri long, nearly half the arm length; longest cirrus segments twice as long as broad; synar- 

 thrial tubercles very high and prominent, as high as broad at the base; 16-17 arms; 42-50 



cirrus segments (Kei Islands and Timor; 73-90 meters) diana (p. 360) 



c". Cirri shorter, their length not more than one-third the arm length; synarthrial tubercles not 

 developed 

 d'. Cirrus segments 38-55 in number 



e'. Longest cirrus segments nearly twice as long as broad; cirri with 38-41 segments; 14 



arms 85 mm. long (Kei Islands; 85 meters) sappho (p. 361) 



e'. Longest cirrus segments not longer than broad 

 p. Cirri slender and short, less than one-fifth the arm length, with 42-55 segments; 20 



arms (Andaman Islands; 302 meters) spinosissima (p. 364) 



p. Cirri longer, from one-fourth to one-third the arm length, with 39-46 segments 

 ff'. Arms very narrow; distal edges of the brachials rather strongly produced; distal 

 edges of the cirrus segments prominent; cirri more than one-third of the arm 

 length, and rather slender; first segment of Pi with a high rounded dorsal process, 

 and from half again to twice as broad as the second; first segment of Pj with a 

 prominent higli dorsal process; 15-20 arms (Philippine to the Lesser Sunda 



Islands; 77-113 meters) alecto (p. 367) 



g'. Arms broader and more rounded dorsally; distal edges of the brachials less pro- 

 duced; cirri less than one-third of the arm length and stouter, the distal edges 

 of the segments not modified; first segment of Pi not produced dorsally, and 

 only slightly broader than the second; first segment of P2 without a dorsal process; 



20 arms (west coast of Australia; 146-219 meters) conaminis (p. 366) 



d'. Cirrus segments 35 in number; 20 arms (southern Japan; 20-600 meters). 



multicolor (p. 369) 



NEOMETBA GORGONIA A. H. Clark 



Plate 36, Figure 190 



[See also vol. 1, pt. 2, figs. 839-842 (side- and covering-plates), p. 405.] 



Neometra gorgonia Alexander, Rec. Western Australian Mus., vol. 1, pt. 3, 1914, p. 108 {nomen 

 nudum.; between Fremantle and Geraldton). — A. H. Clark, Rec. Western Australian Mus., 

 vol. 1, pt. 3, 1914, p. 115 (discovery; faunal relation-ships) , pp. 125-128 (between Fremantle 

 and Geraldton, 80-120 fms. ; description of the type specimen, and characters of the others), 

 p. 131 (specific characters; range); Internat. Rev. gesamt. Hydrobiol. und Hydrogr., 1915, 

 p. 225 and following (detailed account of distribution). — H. L. Clark, Biol. Results Fishing 

 Experiments F. I. S. Endeavour, vol. 4, pt. 1, 1916, p. 6 (characteristic of west Australian sub- 

 region). — A. H. Clark, Unstalked crinoidsof the Sihogra-Exped., 1918, p. 132 (in key; range).— 

 GiSLifiN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 25. — H. L. Clark, 

 Mem. Mus. Comp. ZooL, vol. 55, 1938, p. 41 (notes on a paratype). — H. L. Clark, Echinoderm 

 fauna of Australia, 1946, p. 54 (locality). 



Diagnostic features. — The dorsal processes on the outer cutus segments are triple, 

 consisting of a high median keel with a similar keel but little shorter and lower on 

 either side of it; there are about 40 arms; the cirri are very stout with 39-50 segments; 

 and the division series, brachials and cirrus segments have unmodified distal ends so 

 that the animal presents a smooth appearance. 



Description. — The centrodorsal is discoidal, broad, with a broad and flat bare 

 polar area from 5 to 6 mm. in diameter. The cirrus sockets are arranged in one and a 

 partial second crowded and irregular marginal rows. 



