252 NEW STARFISHES AND OPEIURANS—VEBRILL. vol.xvii. 



more elevated, until close to the lower end some of those on the middle 

 of the plate are relatively larger, higher than broad, with distinctly- 

 enlarged or capitate, rounded ends. The lower marginal plates 

 correspond to the upper ones in number and nearly in breadth, but the 

 sutures along the sides of the rays are not always closely coincident. 



The plates occupying the interradial regions are nearly horizontal 

 and somewhat wedge-shaped, with the breadth radially more than three 

 times the transverse length, but along the sides of the rays they rise 

 upward more, and the length increases in })roportion to the height, as 

 in the case of the upper ones. Their outer surface is covered with 

 rather stout, mostly fusiform, very acute spinules, equal in size 5 the 

 larger ones in length are about equal to one-half the lesser diameter 

 of the plate, and form three or four irregular radial rows, with the 

 smaller aud.more slender ones interspersed. All the spines are loosely 

 appressed to the plates and directed upward and outward in the pre- 

 served specimens, but they are not closely crowded and are scarcely 

 imbricated. In smaller specimens, about half grown (radius, 60 mm.), 

 the spines on the lower marginal plates are mostly not fusiform, bu(, slen- 

 der and regularly tapered, and they form but three regular rows on the 

 middle of the plates, while the smaller and shorter spinules are very 

 slender and much more numerous. The edges of these plates are bor- 

 dered by one or two rows of small, slender, elongated, short, curved 

 spinules or papillte, which meet across the rather deep sutures, thus 

 forming distinct but loose fascioles. The actinal interradial areas are 

 large and covered with a close pavement of plates, with their outlines 

 concealed by the integument in well-preserved specimens; when the 

 spinules are removed, the plates are squarish with rounded corners, 

 strongly convex, with deep, groove-like sutures between them; they are 

 somewhat irregularly arranged, and form a pavement-like area, in which 

 the rows next the adambulacral plates are parallel with the latter and 

 the outer ones are parallel to the marginal i)lates, and slightly imbri- 

 cated; the inner ones are smaller and more numerous than the adam- 

 bulacral plates, usually one, but frequently two, corresponding to each 

 adambulacral plate; in general they are arranged so that two rows start 

 from each marginal i)late, and each row runs to a single adambulacral 

 plate, but an additional row is interpolated in some cases. The row 

 of these plates next to the adambulacral extends out to about the mid- 

 dle of the ray, the distal plates becoming small and narrow. Each of 

 the interradial plates, except those next to the adambulacral series, 

 bears on the middle, one to three, or more, rather large, fusiform, acute 

 spinules, similar to the larger ones on the lower marginal plates, and an 

 irregular open marginal series of much smaller and more slender spin- 

 ules of nearly the same form, but the plates next the adambulacral 

 have their lateral margins bordered by a regular close series of flat- 

 tened papillte, forming distinct lascioles; and occasionally similar fas- 

 cioles appear on a few of the other plates of the second row. The 



