298 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



arc broadened and doubly carinate. Here and there the edges of the segments are 

 beset with teeth and spines. The pinnules of the middle of the arm, from about the 

 thirty-fifth brachial onward, are about 7 mm. long with 15-17 segments of which the 

 two basal are short and broad, those following elongate. In contrast to the middle 

 pinnules of var. insculpta, from which they differ sharply in the greater number of seg- 

 ments, they are entirely smooth, as the distal ends of the segments are not produced. 

 Toward the arm tips the length of the pinnules seems to increase somewhat. Wherever 

 gonads are developed on the pinnules, as on P 3 , the two or three segments covering them 

 are markedly broadened. 



The ambulacral plating consists of prominent side and covering plates. Sacculi 

 are of medium size and inconspicuous. The disk is as deeply incised as that of var. 

 insculpta. 



Locality. — West Indies. 



CRINOMETRA BREVIPINNA Tar. CONCINNA A. H. Clark 



[See vol. 1, pt. 1, figs. 206, p. 239, 276, p. 260, 492, p. 367; pt. 2, figs. 76, 77, p. 53, 302, p. 223, 678, 



p. 338.] 



Crinometra concinna A. H. Clark, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 646 (description; Albatross 



station 2342). 

 Antedon brevipinna var. elegans Hartlaub, Mem. Mus. Comp. Zool., vol. 27, No. 4, 1912, p. 322 (in 



key), p. 331 (description; Blake station 193), pi. 4, fig. 7, pi. 11, fig. 5. 

 Crinometra gracilis H. L. Clark, Univ. Iowa Bull. Lab. Nat. Hist., vol. 7, No. 5, 1918, p. 10 (Bahama 



Expedition station 2). 



Description. — The centrodorsal is a flattened hemisphere with the bare polar 

 area 3 mm. in diameter and thickly beset with long tubercles. The cirrus sockets 

 are arranged approximately in 10 crowded columns, two or three to a column, the 

 columns sometimes separated by strongly tubercular ridges. 



The cirri are XX, 14-18 (usually 15 or 16), from 25 to 30 mm. long. The first 

 segment is very short, the second and third are about twice as broad as long, the fourth 

 is nearly or quite as long as broad, and the remainder are about one-third again as 

 long as broad, becoming slightly shorter distally; the antepenultimate segment is 

 longer than those preceding, half again as long as broad, and the penultimate segment 

 is about twice as long as broad, its width being somewhat less than that of those pre- 

 ceding. The cirrus segments have their distal ends somewhat enlarged and slightly 

 overlapping, this feature being most marked on the dorsal side of the outer half of the 

 cirri. The opposing spine is minute, terminally situated, and directed obliquely 

 forward. The terminal claw is not so long as the penultimate segment, stout basally 

 but rapidly tapering distally, moderately curved. 



The ends of the basal rays are visible in the angles of the calyx; they bear one or 

 more long tubercles. 



The radials are concealed. The IBri are very short, often more or less concealed 

 by the centrodorsal, bandlike and curved or narrowly erescentic. The IBr 2 (axillaries) 

 vary from rhombic to approximately triangular, and are two-and-one-half times as 

 broad as long; their lateral borders are as long as those of the IBri and are often, like 

 them, reduced to a point. The IIBr series are usually 2; in eight specimens one IIBr 

 series is 4(3+4), and two are 4, the ossicles united in two synarthrial pairs. The 

 II I Br scries are 2, developed interiorly in 1. 2, 2, 1 order. The edges of the ossicles 



