WEST INDIAN STARFISHES 



161 



These small spines are situated on the outer or descending curv- 

 ature of the plate. Small, regular, rounded, closely-packed 

 granules cover the rest of the outer surfaces of the plates, but the 

 sides in the fasciolated furrows are densely covered with very 

 slender, elongated spinules, much finer than the granules. The 

 grooves between the plates are wide and deep. 



The dorsal paxillar area is nearly even. The paxillae are 

 closely packed, stellate ; those along the middle are quite as large 

 as the lateral ones. Each of the larger ones bears about six to 

 eight divergent, marginal, short, clavate or capitate spinules, 

 surrounding one, or sometimes two, of the same size and form. 

 At the very center of the disk there is a small area of much 

 smaller and finer paxills, on a slight elevation. 



The madreporic plate is partially visible, closely surrounded 

 by the normal paxillae ; it is not far from the marginal plates. 



The inferomarginal plates bear two nearly equal, stout, slight- 

 ly curved, marginal spines, side by side. On the proximal half 

 of the ray these are much flattened, lanceolate or oblong lanceo- 

 late with rather acute tips; those in the interradial angle are 

 shorter and flatter; those beyond the middle of the ray are less 

 flattened and more acute. The longest are scarcely equal in 

 length to the radial length of two of the adjacent superomar- 

 ginal plates. 



Extending downward from the outer of these spines, and bor- 

 dering the aboral margin of the plates there is a spaced row of 

 about five smaller, flattened, usually appressed, acute spines ; the 

 upper one, close to the base of the marginal, is about half as long 

 as the latter ; the others decrease gradually in size. Another less 

 marked row of similar but smaller spines borders the adoral 

 margin of these plates. The rest of the outer surface is closely 

 covered with small, flat, blunt, mostly short, scale-like, imbricated 

 spinules. These are often as wide as long. 



The adambulacral plates, when well developed, have a furrow 

 series of three rather stout, flat, truncate, divergent spinules; 

 toward the mouth there are often four spines. These are nearly 

 equal in size, but the middle one is slightly longer and vertically 

 compressed, and is seated on the slightly prominent angle of the 

 plate. The others are thin and slightly wider near the distal 

 end. Back of these, on the actinal side, are two flat, truncated, 



