82 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



h l . Elements of the IBr series and first 2 brachials short and very broad, in close 

 apposition with their neighbors on either side; segments of the genital pin- 

 nules short and broad, in the basal half of the pinnules usually much broader 

 than long, and more or less produced aborally; cirri short, rather stout, and 

 usually few in number. 



i 1 . Elements of the IBr series and first 2 brachials united by syzygy, or by an 

 exceedingly close synarthry which appears externally as a uniformly nar- 

 row, or dotted, line; 2 or more of the basal segments of the proximal pin- 

 nules usually bear a prominent cariuate process (Ceylon and the Gulf of 

 Martaban to tropical Australia, south to between Fremantle and Gerald- 

 ton on the west and Sandon Bluffs on the east, northward to Luzon, the 

 China Sea and Hong Kong, and eastward possibly to the Society Islands; 



0-109 meters) Comatula, p. 302. 



i 1 . Elements of the IBr series and first 2 brachials united by synarthry, the line of 

 union appearing externally as 2 very narrow triangles converging to a 

 common apex in the median line; no prominent carinate processes on the 

 basal segments of the proximal pinnules (Cape Lookout, N. C., southward, 

 throughout the Caribbean Sea, to Rio de Janeiro; 0-508 [7510] meters). 



Comactinia, p. 374. 



h?. Elements of the IBr series longer and narrow, free lateral!}' and widely separated 

 from their neighbors; segments of the genital pinnules beyond the first 2 as 

 long as, or longer than, broad; cirri long, slender, and numerous (southwest- 

 ern Japan to the Lesser Sunda Islands; 311-984 meters) . Comatulides, p. 400. 

 1 . More than 30 cirrus segments which, except for the penultimate, are twice as 

 broad as long or even broader (southwestern and southern Australia from 

 Perth, Western Australia, to Port Phillip, Victoria; 0-18 meters) . 



Comatulella, p. 295. 



e 2 . Terminal comb on the proximal pinnules very long, usually arising at about, or even 

 within, the end of the proximal third of the pinnules; teeth of the combs usually 

 much exceeding in height the width of the segments that bear them; fourth-seventh 

 brachials with prominent spinous median dorsal knobs or keels (Key West, Fla., 



to Cape Lookout, N. C.; 14-241 meters) Comatonia, p. 288. 



d*. Combs on the proximal pinnules with 3 teeth only; cirri excessively slender and thread- 

 like, the enormously elongated segments with greatly swollen articulations; the penul- 

 timate segment, which is much shorter than those preceding, is twice as long as broad; 

 arms not more than 15 mm. in length (Virgin Islands; 91-183 meters). 



Microcomatula, p. 287. 

 c 2 . Second, third, and fourth pairs of pinnules absent, so that there are no pinnules between 



PI and P 5 and P and P e (off Georgia; 512 meters) Comatilia, p. 284. 



6 1 . Cirri absent, the centrodorsal being reduced to a stellate, pentagonal, or more or less irregular 

 plate (Gulf of Martaban and the Andaman Islands to Australia, south on the east coast 



to Sandon Bluffs, New South Wales; 0-109 meters) Comatula, p. 302. 



a 1 . More than 10 arms. 

 6'. Cirri present. 



c 1 . First pinnule of the undivided arms arising from a IIBr or subsequent axillary on the first 

 brachial, and a syzygy between brachials 2 + 3; IIBr series 4 (3 + 4), or 4 (3 + 4) and 2; 

 IIIBr and following division series, if present, and very exceptionally the IIBr series, 3 

 (2 + 3); division series sometimes very irregular. 



d l . Distal cirrus segments more or less strongly carinate dorsally, with a dorsal tubercle or 

 small spine in the middorsal line, or a V-shaped row of tubercles, of which the largest 

 is at the apex of the V. 



e 1 . Brachials much broader than long, wedge-shaped or oblong (Madagascar, Mauritius, 

 the Maldive Islands, and Ceylon to northern Australia, the Caroline Islands, south- 

 western Japan, the Philippines, and Formosa [Taiwan]; 0-292 meters). 



Capillaster, p. 156. 



