CLARK: BRITTLE-STARS. 293 



Disk 5 mm. in diameter; arms about 60 mm. long. Disk covered 

 by a coat of rather fine scales, which are, however, much coarser 

 around the radial shields; near the center of the disk there are 75-80 

 scales per square mm.; all (or nearly all) the disk-scales have the 

 distal margin swollen into a conspicuous papilla or lump, the height 

 of which may equal the diameter of the scale. Radial shields long and 

 narrow, the length sometimes equalling four times the width of the 

 distal end; they are separated proximally by several scales and are 

 only in contact for the distal third. Upper arm-plates broadly oval 

 or rounded hexagonal, nearly twice as wide as long, only in contact 

 in the median line. Interbrachial areas below very sparsely covered 

 with minute, more or less papilliform scales. Oral shields almost 

 twice as long as wide, rounded pentagonal, equally wide distally and 

 proximally; madreporite much larger than the others and nearly 

 as wide as long. Adoral plates rather small, irregularly triangular 

 with concave sides and rounded angles; they meet interradially and 

 their distal corners tend to separate the oral shield from the first side 

 arm-plate. Oral plates rather large, the proximal end distinctly 

 swollen. Oral papillae, four on each side; the first (most proximal) 

 is thick and block-like and is more or less distinctly separated from its 

 fellow (on the other side of the jaw) by the lowest tooth; the second is 

 small and papilliform while the third is much wider and flatter; these 

 first three papillae are all borne on the oral plate and are well-spaced 

 from each other; the fourth papilla, which is about equal to the second 

 but is a little flatter and more circular, is borne on the outer proximal 

 angle of the first under arm-plate, and is well-spaced from the third. 

 First under arm-plate rather large, somewhat pentagonal with rounded 

 corners, wider than long; succeeding plates about as long as wide, 

 pentagonal with rounded corners, the distal margin more or less con- 

 cave, barely in contact with each other. Side arm-plates moderate, 

 each with three subequal, slender, pointed arm-spines about as long 

 as the segment. Tentacle-scale single, small, rounded, borne on the 

 side of the under arm-plate. Color, in life and preserved, disk pale 

 gray; arm-spines white; arms white or brownish white; many upper 

 arm -plates obscurely blotched or shaded with light dusky purple. 



The paratype has the disk 4 mm. across and the arms are scarcely 

 40 mm. long. The primary plates (11) of the disk are very distinct 

 and are perfectly flat. The interbrachial areas below are uniformly 

 covered with small lumpy scales. The oral shields are not much 

 longer than wide. In all other particulars, the smaller specimen 

 agrees remarkably well with the larger, but there is very little of the 



