308 BULLETIISr 100, UNITED STATES NATIONAL MUSEUM. 



is a single marginal series of small elongate 4-sided granules over- 

 hanging and closing a very narrow groove or channel. A very few 

 plates have a tiny 2-jaAved narrow spatulate pedicellaria near the 

 inner margin. Terminal plate wider than long, rather large, tuber- 

 cular, and cordiform, the surface roughened by minute elevations, 

 but without granules. 



Inferomarginals corresponding to superomarginals and much less 

 tumid, the surface being smooth and Avithout irregular roughening 

 or elevations (except on the last 3 or 4 plates). The plates form a 

 rounded margin to the ray, the actinal surface being wider than the 

 lateral, and as seen from below the first plate is a trifle wider than 

 long, while the remainder are a trifle longer than wide. Marginal 

 granules similar to those of superomarginals. 



Actinal intermediate plates squarish, smooth, very slightly tumid, 

 arranged in 3 chevrons with an extra plate adjacent to marginal in- 

 terradially. The interradial plate at the apex of the 2 outer 

 chevrons is the largest of its series, but the innermost chevron has 

 small paired plates behind the mouth plates. What appears to be 

 the odd interradial of that chevron is really the second enlarged plate 

 in the left arm of the chevron, the corresponding right plate being 

 small and wedged out of place. The former usually bears a slender 

 spatulate pedicellaria. The plates are all margined by oblong gran- 

 ules in a single series. 



Adambulacral plates small, wider than long, with proximally a 

 slightly convex furrow margin which becomes distally more convex. 

 Furrow spines small, 3 or 4, about as large as the plate, thick, sub- 

 truncate, and crowded. Near the end of the ray these are reduced 

 first to 2 (of which the aboral is the larger) and finally to 1. Back 

 of these are 2 shorter compressed, rounded or subtruncate granules, 

 as wide or wider than high, with flat side to furrow and occupying 

 the whole length of the plate. These are followed by 4 or 5 smaller 

 prismatic granules, in 2 series, or simply bordering the small plates 

 so that they appear in 2 series. The small distal plates which have 

 only 1 furrow spinelet, have usually 1 subequal, subambulacral spine- 

 let with 1 to 3 additional granules. Although the subambulacral is 

 slightly enlarged over the furrow spines at the end of the ray, it is 

 not markedly so, and would not naturally be considered as an en- 

 larged spine. Instead of the adoral granule of the first series, a few 

 plates bear a pedicellaria with 2 spatulate smooth jaws which open 

 across the plate, the outer jaw reaching the marginal granules. 



Mouth plates small, flat, triangular, with a straight furrow margin 

 having 6 spinelets, the inner 2 compressed and enlarged. Suboral 

 granules, a series of 4 parallel with the furrow series and similar to 

 the subambulacral ; back of these, a series bordering the median and 

 outer suture, similar to the outer granules of the adambulacrals. 



