34 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



centrodorsal is rather thin discoidal with sloping sides and a rather strongly concave 

 dorsal pole. The cirrus sockets are arranged in a single marginal row, with a few 

 additional sockets representing a partial second row alternating with the first. 



The cirri are IX, 32-33, about 16 mm. long. The first segment is very short, 

 between three and four tunes as abroad as long, and the fourth is about twice as broad 

 as long. The sixth and following segments are about half again as broad as long. 

 The first segment is slightly broader than the second, and the cirri taper almost 

 imperceptibly distally. From the tenth or eleventh onward each cirrus segment 

 bears dorsally a pair of small low blunt tubercles situated side by side. These occupy 

 about the central half of the dorsal surface, the outer quarter on each side of them 

 being free. On the last six or seven segments before the penultimate the tubercles 

 become glassy, conical, and sharp. On the antepenultimate segment they are com- 

 monly absent; if present, they are usually fused into a low transverse ridge. The 

 opposing spine is single, prominent, conical, glassy, median in position, and erect, 

 arising from the entire dorsal surface of the penultimate segment and equal to about 

 half the width of that segment in height. The terminal claw is scarcely so long as 

 the penultimate segment, and is stout, rapidly tapering, and strongly curved. 



The radials are approximately oblong with the distal border slightly and regularly 

 concave, and are about six times as broad as the lateral length. They are hi lateral 

 contact. The IB^ are nearly or quite twice as long as the radials, and are about four 

 times as broad as long. Their sides are parallel, but the ventrolateral border is pro- 

 duced in the distal two-thirds into a flangelike process which is highest at the distal 

 end. The IBr 2 (axillaries) are broadly pentagonal, twice as broad as long, with the 

 short lateral border produced ventrolaterally into a flangelike process somewhat 

 broader than that on the IBri and of uniform height. The proximal and distal sides 

 are almost straight. The IIBr series resemble the IBr series, but the flange on the 

 outer side of the IIBri runs the entire length of the segment, and is as high as that on 

 the axillary preceding. The division series are strongly convex dorsally, evenly 

 rounded, and perfectly smooth, with no indication of synarthrial tubercles. 



The 20 arms are 100 mm. long, all the ten IIBr series being developed. The first 

 brachials are slightly wedge-shaped, the interior length being about two-thirds the 

 exterior, and are about twice as broad as the median length. Their inner sides are 

 completely in contact, or their inner distal angles may be separated by a slight notch. 

 The outer sides are produced ventrolaterally into a broad flangelike process of which 

 the crest is straight with broadly rounded angles, which is as broad as that on the seg- 

 ments preceding. The second brachials resemble the first, but exteriorly the flangelike 

 process is displaced by the pinnule. The first syzygial pair (composed of brachials 

 3+4) is oblong, half again as broad as long. The next four brachials are approxi- 

 mately oblong, about three times as broad as long, that immediately succeeding is 

 wedge-shaped, and those following are triangular, half again as broad as long. In the 

 outer half of the arm the brachials become wedge-shaped again, then less obliquely 

 wedge-shaped, and finally elongate. 



P! is 7 mm. long with 17-20 segments, rather slender, and tapers gradually to a 

 delicate tip. The segments become about as long as broad on the fourth, and ter- 

 minally are about twice as long as broad. 



Pa is 7 mm. long with 11-14 segments, much stouter than P 1 and very stiff and 



