WEST INDIAN STARFISHES 185 



sutures. They do not rise much above the paxillar area, nor 

 encroach much upon it, but yet form a regular raised border. 



Their outer surfaces are covered with very small, acute, spaced 

 spinules; at the sutures these change rather abruptly into the 

 longer closely fasciolated spinules. Nearly always there are no 

 traces of spines or tubercles on these plates, but very rarely a 

 small conical spine occurs on one to three of the proximal plates, 

 but with no regularity nor constancy. 



The inferomarginal plates project laterally a little beyond the 

 upper ones; their lower side is flattened, and usually a little 

 thickened at the aboral margin. They bear two slender, elonga- 

 ted, slightly flattened and very acute marginal spines ; just above 

 the base of each there is sometimes a small papilliform pedicel- 

 laria. The under side is covered with suberect, very acute, small, 

 spaced spinules and small spines of various sizes; the larger ones 

 form an aboral submarginal row, but others occur irregularly. 



Interactinal plates are few and small, next the jaws; they are 

 spinulose and often have a central pedicellaria. 



The adambulacral plates have a furrow-series, usually of three 

 slender spines distally, but often with four or five proximally. 

 The second and third rows, when there is no pedicellaria, usually 

 consist each of three or four slender, nearly equal spines, the 

 outer ones a little smaller. 



Often there is a large papilliform pedicellaria, usually with 

 three valves, which replaces all or most of the spinules of the 

 second row ; if any remain they are on the adoral side. 



The valves of the pedicellariae are usually strongly spatulate, 

 incui'ved somewhat, and truncate or notched at the tip. Al- 

 though most have three valves, some have four, and others have 

 but two. 



The madreporic plate is large, with deep gyri. It is usually 

 wholly or partly exposed and separated from the marginal plates 

 by only one or two rows of paxillae. 



The ocular plate is small, about as wide as long, deeply bi- 

 lobed, and with a proximal notch. 



The jaw-plates are narrow and much elevated, densely covered 

 with small slender epioral spines, the two clusters convergent. 

 Adoral spines similar and very numerous. Peroral spines nu- 

 merous, some much thicker ones at the apex are obtuse. 



