452 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Comaster serrate A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 317 (southern Japan); vol. 

 39, 1911, p. 533 (compared with C. distincta; identity of the Owston specimens from Sagami 

 Bay); Crinoids of the Indian Ocean, 1912, p. 89 (range); Journ. Washington Acad. Sei., vol. 5, 

 No. 6, 1915, p. 214 (southern Japanese species; range and its significance); Unstalked Crinoids 

 of the Siboga Exped., 1918, p. 37 (in key; range). GISLEN, Kungl. svenska Vetenskap. Handl., 

 vol. 59, No. 4, 1919, pp. 17, 18 (discussion); Nova Acta reg. Soc. sci. Upsaliensis, ser. 4, vol. 5, 

 No. 6, 1922, p. 37 (Bock's stations 45, 55, 59; notes); figs. 21-25, p. 44); Zool. Bidrag fran 

 Uppsala, vol. 9, 1924, p. 77 (syzygies) ; fig. 64, p. 75 (syzygial face) . 



Phanogenia serrate A. H. CLARK, Proc. U. S. Nat. Mus., vol. 35, 1908, p. 124 (listed). 



Comanthus serrate A. H. CLARK, Zool. Anzeiger, vol. 34, No. 11-12, 1909, p. 366 (listed). 



Diagnostic features. The arms are 30 in number, and the cirri have 9-11 seg- 

 ments, of which the longest is three times as long as broad. 



Description. -The centrodorsal is discoidal, circular or more or less pentagonal 

 in outline, moderately thick, with the somewhat convex polar area 2 or 3 mm. in diam- 

 eter. The cirrus sockets are arranged in 2 crowded and irregular alternating rows. 



The cirri are XXIV, 9-10, from 7 to 9 mm. in length. The first segment is not 

 quite so long as broad, the second is from half again to twice as long as broad, and the 

 third and fourth are the longest, approximately equal in length though the third is 

 sometimes slightly the longer, about three times as long as the width of their ends. 

 The following segments decrease rapidly in length so that the penultimate is little, if 

 any, longer than broad. The fifth is a more or less marked transition segment. The 

 second-fifth segments are strongly constricted centrally with expanded ends, this 

 feature dying away distally. The fifth and following segments have the submarginal 

 portion of the distal dorsal surface raised into a prominent transverse finely serrate 

 ridge which at first is almost or quite straight and nearly or quite as broad as the distal 

 width of the segment, but gradually becomes, in end view, narrower and more rounded, 

 and finally sharply triangular, but not increasing in height or becoming more proxi- 

 mally situated. On the penultimate segment this gives place to a single terminal 

 spine which is slender and prominent, though rather short, erect, subterminal to 

 median in position, in height equal to one-fifth or one-fourth of the width of the seg- 

 ment. The terminal claw is long and slender, moderately curved, half again as long as 

 the penultimate segment. 



The ends of the basal rays are visible as rather prominent tubercles in the interra- 

 dial angles of the calyx where they bridge over the narrow clefts between the radials 

 and the centrodorsal. 



The distal ends of the radials are even with the edge of the centrodorsal or extend 

 slightly beyond it. The anterolateral angles of the radials are produced distally in the 

 interradial angles where they entirely separate the bases of the IBr^ The IBr! are 

 very short, five or six times as broad as long in the median line, with the distal border 

 straight and the proximal more or less convex so that the lateral length is usually not 

 so great as the median. The IB^ are laterally widely separated by a broad U-shaped 

 gap, and are united to the IBr 2 by a pseudosyzygy which usually consists of an 

 ordinary synarthry modified by the presence of three or four concentric rows of uni- 

 form low tubercles in each ligament fossa, but which may be further modified by the 

 resolution of the dorsal half of the longitudinal ridge into four or five converging 

 radial ridges. The IBr 2 (axillaries) are broadly triangular, about twice as broad as 



