286 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



minal claw is approximately equal in length to the penultimate segment, moderately 

 stout and evenly curved. 



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

 radial angles. 



The radials are very short in the median line, but extend well up in the inter- 

 radial angles and separate the bases of the IBrj for a distance about equal to one-half 

 of the basal diameter of those ossicles. The IBrj are comparatively small, oblong, 

 very short, between thi-ee and four times as broad as long. The IBro (axillaries) 

 are broadly pentagonal, about twice as broad as long, the lateral edges about as 

 long as those of the IBri with which they make an obtuse angle. 



Arms 10, about 30 imn. long. The first brachial is very short, oblong, about 

 fom- times as broad as long, united basally with its fellow, but diverging from it at 

 approximately a right angle distally. The second brachial is usually about twice as 

 large, wedge-shaped. The first syzygial pair (third and fourth brachials) is somewhat 

 longer than broad. The following brachials are very obliquely wedge-shaped, at 

 first about as long as broad, but almost immediately becoming longer than broad and 

 gradually increasing in length, being terminally two or three times as long as broad 

 or even longer, with expanded ends. After about the sixth the brachials develop 

 strongly produced and overlapping distal ends which are armed with a row of com- 

 paratively coarse spines. 



Syzygies occur between brachials 3 + 4, again between brachials 13 + 14, and 

 distally at intervals of 2 muscular articulations. 



There are no pinnules on the fifth-tenth brachials, Pz, Pg, Pi, Pt,, Pc, and P<j, being 

 absent. Pi is from 4 to 4.5 mm. long, slender and tapering evenly distally, composed 

 of 20 segments, of which the first is not so long as broad, the second and third are 

 about as long as broad, and the remainder are about half again as long as broad. The 

 segments are somewhat constricted centrally and have expanded and overlapping 

 distal ends wliich are armed with fine spines, and a finely spinous dorsal surface. 

 The terminal comb is very prominent, composed of from 6 to 8 large teeth which are 

 trapezoidal or bluntly triangular, their bases in contact, somewhat higher than the 

 height of the segments which bear them, and recurved. Pa is similar to P,. Ps (the 

 pinnule following PO is 3 mm. long with 12 segments, of which the first 2 are not so 

 long as broad, the third is about as long as its proximal diameter, and the remainder 

 are somewhat longer than broad. All but the first have greatly expanded distal ends 

 armed with comparatively coarse spines. A strongly rounded and prominent gonad 

 occupies the second-foui-th or second-fifth segments. The following pinnules slowly 

 increase m length, the segments, except the first 2, slowly becoming more and more 

 elongated. The distal pinnules are about 4.5 mm. long, or about the length of the 

 oral pinnules. The gonads occur on from 3 to 6 pinnules on either side of the arm 

 and are always small and basally situated. 



Large, conspicuous, and well-formed covering plates are present, 5 to each 2 

 pmnulars. These are considerably higher than the lateral diameter of the pinnulars, 

 extend outwaid and slightly distally, and are somewhat more than twice as long as 

 broad and strongly constricted centrally, so that they appear as two similar circles 

 joined by a broad neck; then- reticulation is very fine, and their borders are regular, 

 though unfinished. 



