162 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Diagnostic features. — The size is large, and the cirri are large, stout, and numerous 

 with 26-40 segments, of which the distal are much broader than long. There are 

 40-110 (usually over 60) arms. This species is more easily confused with Comatella 

 nigra than it is with any other species of Capillaster. 



Description — The centrodorsal is thick discoidal or almost columnar, with the 

 bare polar area moderate in size, from 3 to 5 mm. in diameter, usually more or less 

 strongly concave, rarely flat or somewhat convex. The cirrus sockets are arranged 

 in 2 or 3 closely crowded more or less irregular alternating marginal rows. 



The cirri are XVI-XXX (most commonly XX-XXV), 30-40 (usually nearer 

 the former), from 30 to 40 mm. long. The first segment is very short, and the 

 following slowly increase in length to the sLxth (more rarely the seventh or eighth) 

 which is about as long as broad; the next 4 or 5 segments are subequal, all slightly 

 longer than broad (usually about one-third longer than broad), and those following 

 decrease in length, soon becoming about twice as broad as long, or even shorter, 

 and remaining of these proportions until the end of the cirrus. A more or less, 

 usually fairly well, differentiated transition segment occurs at about the tenth or 

 eleventh, proximal to which the segments are dorsally rounded without dorsal proc- 

 esses, with a dull surface and comparatively dark in color, while distally they are 

 light in color, highly polished, and with distal projections on the dorsal side. The 

 tenth and following segments have the distal dorsal edge produced forming a coarsely 

 dentate transverse ridge, usually with 5-7 distinct teeth, though these may be more 

 or less obsolete. In lateral view this ridge appears as a small or moderate terminal 

 or subterminal dorsal spine which may be single or bi- or tri-cuspid. 



Distally this ridge becomes progressively narrower, on the outermost 12 or 13 

 segments being represented merely by paired dorsal spines or, more rarely, by single 

 spines. The opposing spine is always single, median, submedian or terminal, erect, 

 or directed slightly distally, stout, and short, rarely reaching more than one-third 

 the width of the penultimate segment in height. The terminal claw is from half 

 again to twice as long as the penultimate segment, stout, abruptly curved basally 

 but becoming nearly straight distally. 



The ends of the basal rays are very prominent in the interradial angles of the 

 calyx, bridging over the narrow clefts between the radials and the centrodorsal and 

 causing the proximal surface of the centrodorsal to assume a peculiarly stellate 

 outline. 



The radials are short and oblong, usually about half as long as, though sometimes 

 fully as long as, the IBr,. The IBri are oblong, short, four or five times as broad 

 as long or even broader, united interiorly for almost theii- entire length. The IBrj 

 (axillaries) are broadly pentagonal, almost triangular, about two and one-half times 

 as broad as long, with their sides rounded and well separated from those of their 

 neighbors; the lateral edges are slightly shorter than those of the IBri. The IIBr 

 series are 4 (3 + 4), rounded dorsally and laterally and well separated. The IIIBr 

 series, IVBr series, and VBr series are 3 (2 + 3). There is a tendency to develop 

 one more division series on the inner side of the IIBr and IIIBr series than on the 

 outer. 



Arms 40-85 (rarely under 60) in number, from 80 to 130 mm. long. The first 

 b^-achials are wedge-shaped, about twice as broad as the interior length, almost 



