A MONOGRAPH OP THE EXISTING CKINOIDS 113 



B. M.; Challenger Sta. 186; west reef, Hululo, Male, Maldives; outer part of reef at Rotuma; 

 Salomon, reef; characters of the specimens). REICHENSPEKGER, Abhandl. Senck. naturf. 

 GeseUsch., vol. 35, Heft 1, 1913, p. 83 (Ceylon); p. 84 (Ceylon; Doctor Sarasin; characters 

 of the specimen). A. H. CLARK, Internat. Revue d. gesarnt. Hydrobiol. u. Hydrogr., 1915, 

 pp. 222 and following (detailed account of the distribution in Australia). H. L. CLARK, 

 Carnegie Institution of Washington Publication 212, 1915, p. 101 (common at Mer); pp. 107 

 and following (habits and reactions). A. H. CLARK, Unstalked Crinoids of the Siboga Kxped., 

 1918, p. 4 (in key; range); p. 7 (synonymy; detailed account; Stas. 89, 96, 213); pp. 272, 

 274 (listed). H. L. CLARK, The Echinodcrm Fauna of Torres Strait, 1921, p. 5 (history); 

 p. 8 (collected by the Carnegie Exped., 1913); p. 12 (Mer; notes; habits and reactions; color); 

 pp. 192 and following (range); pi. 3, fig. 1 (colored). GISLEN, Nova Acta reg. Soc. sci. Upsali- 

 ensis, ser. 4, vol. 5, No. 6, 1922, p. 16 (Bock's stations 53, 59; notes); figs. 4-6, p. 28. 

 Adinometra mulliradiata BELI/, Trans. Linn. Soc. (Zool.), ser. 2, vol. 13, pt. 1, 1909, p. 20 (Salomon; 

 Coin Peros). 



Diagnostic features. The size is rather small; the cirri are small and weak, 

 composed of 16-20 segments and 10 mm. in length; there are 19-20 arms which are 

 between 70 and 80 mm. long; IIIBr series are not developed. 



Description. The centrodorsal is discoidal, with a broad flat polar area from 

 3 to 4 mm. in diameter. The cirrus sockets are arranged in from 2 to 3 closely 

 crowded alternating marginal rows. 



The cirri are XVIII-XXXV, 16-20, relatively small and weak, 10 mm. in length. 

 The first segment is short, the second is about as long as broad, the fourth is half 

 again as long as broad, the fifth and sixth are twice as long as broad, and the seventh 

 is a transition segment, half again as long as broad, with the greater part of the 

 surface dull like that of the preceding segments, but the distal portion highly polished 

 like that of the succeeding segments. The following segments decrease in length, 

 being terminally about twice as broad as long. The transition and following seg- 

 ments have a small distal dorsal tubercle which gradually moves nearer the center 

 of the dorsal side and becomes more prominent, on the last 3 segments being median 

 in position. The opposing spine is represented by a small centrally situated sharp 

 tubercle. The terminal claw is longer than the penultimate segment and is stout 

 and strongly curved. When compared with those of C. stelligera or of C. decora the 

 cirri seem disproportionately slender and weak. 



The ends of the basal rays are visible as small tubercles in the angles of the calyx. 



The radials are just visible in the interradial angles over the ends of the basal 

 rays. The IBr! are very short, oblong, not quite meeting basalty. The IBr 2 are 

 broadly pentagonal, about twice as broad as long. The IIBr series are 2; the IIB^ 

 are united interiorly for rather more than the proximal half. IIIBr series are not 

 developed. The division series are widely separated, exposing a strip of perisome 

 equal in width to one-third or one-half the width of the IIBr series. 



Arms 19-20, from 70 to 80 mm. long. The first 2 brachials are similar in shape 

 and size, wedge-shaped, longer exteriorly than interiorly, and about twice as broad 

 as the exterior length. The following 4 brachials are oblong, about twice as broad 

 as long or slightly broader, those succeeding becoming triangular, about half again 

 as broad as long, then gradually changing to wedge-shaped, twice as broad as long, 

 and becoming slightly longer in the extreme distal portion of the arms. The brachials 



