494 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The cirri are absent in fully developed specimens; but there frequently occur 

 occasional small rudimentary cirri irregularly placed around the periphery of the 

 centrodorsal. 



The ends of the basal rays are visible as minute tubercles at the angles of the 

 centrodorsal. 



The radials are very short, distally four or five times as broad as the median 

 length. The IBri vary from slightly longer than to about twice as long as the radials 

 and are in close lateral apposition. The IBr 2 (axillaries) are triangular, two or two 

 and one-half times as broad as long, twice as long as the IBri, and well separated 

 laterally. The IIBr series are 4 (3 + 4), occasionally 2. The IIIBr series are 2, 

 occasionally 4 (3+4). The IVBr and VBr series are 4 (3+4), both occasionally 2, 

 the latter more or less irregular in their occurrence. The IBr 2 (axillaries) and the 

 division series are well rounded dorsally and laterally and rather widely separated 

 laterally. 



The arms are 55-170 (usually 70-100) in number, from 90 to 120 mm. in length. 

 The first 2 brachials are subequal, slightly wedge-shaped, about twice as broad as 

 the exterior length, the first entirely united interiorly, the second free interiorly. 

 The first syzygial pair (composed of brachials 3 + 4) is oblong, nearly or quite twice 

 as broad as long. The next 2 brachials are oblong, twice as broad as long or some- 

 what broader, those following becoming obliquely wedge-shaped or even triangular, 

 twice as broad as long (somewhat longer in small specimens), and gradually short 

 wedge-shaped or even almost discoidal in the outer half of the arms. The elements 

 of the division series have unmodified distal ends, but the second or fourth and 

 following brachials have strongly overlapping distal ends which are armed with fine 

 spines. One or both of the posterior postradial series are usually shorter than the 

 others and ungrooved. 



Syzygies occur between brachials 3+4, again from between brachials 12+ 13 to 

 between brachials 14 + 15, and distally at intervals of 4 or 5 (usually 4) muscular 

 articulations. 



The disk is from 30 to 40 mm. in diameter, naked, or with a few concretions in 

 the large anal area. The mouth is marginal, radial to interradial. The anal tube 

 is approximately central. 



P D is comparatively small and slender, 15 mm. long, composed of 35-40 seg- 

 ments, which at first are broader than long but become about as long as broad on the 

 fifth or eighth and following. The terminal comb has 8-11 small rounded triangular 

 teeth, most of which are ordinarily repeated in reduced form on the inner side of the 

 pinnule. The following pinnules gradually decrease in length and slightly in stout- 

 ness, P P being 12 or 13 mm. long, P t about 10 mm. long, and P 2 7 or 8 mm. long, 

 the last very delicate, with 20-22 segments. P 3 is about 7 mm. long, slightly stouter 

 than P 2 and bearing a gonad. P 4 and the following pinnules are 7 mm. long, slightly 

 stouter than P 3 , with all of the component segments broader than long, with promi- 

 nent and slightly overlapping distal ends and a spinous surface. Distally the pin- 

 nules gradually become more slender, the distal pinnules being about 9 mm. long, 

 slender, with 15-18 segments which have somewhat prominent distal ends and the 

 longest of which are about as long as broad. The terminal combs persists usually 

 as far as P 6 or P 8 , sometimes to P 12 . 



