WEST INDIAN STARFISHES 67 



basal radials or carinals. The madreporite, whieh is triangular, 

 small, and depressed, is bordered externally by two smaller 

 lunate plates, just outside the row of basal carinals. 



The interradial areas, destitute of papulse, are relatively ex- 

 tensive, running up in a narrow area, nearly to the central 

 pentagon. The plates on the interradial areas are rhombic, 

 closely united, and a little convex. 



The median line of each ray is occupied by a row of small 

 elliptical plates, elongated radially, without papulae. The pap- 

 ular pores are large, round, and form six radial rows, where most 

 developed; a few are situated on the central area of the disk. 

 Superomarginal plates are transversely oblong, sometimes con- 

 stricted across the middle, or double, and about twice as large as 

 the roundish inf ero-marginals ; the latter, however, project a 

 little more and thus form the edge of the margin. Both series 

 are covered with sharp granules, like the dorsals. No pedicel- 

 lariae were found. 



Variations. 



A somewhat smaller alcoholic specimen (diameter 28°^™) ap- 

 pears somewhat different. The principal dorsal plates are more 

 distinct and appear more convex and more regularly arranged. 

 The outlines of many of the plates can be seen under the gran- 

 ulated dermis. The upper marginal plates show their outlines 

 beneath the granules. When the granules are cleaned off, they 

 are oblong with rounded angles, with the longer axis transverse 

 to the disk-margins. They are of the same width and number 

 as the lower plates, and about twice as long, vertically. Their 

 width is about the same as that of the adjacent abactinal plates, 

 and they are covered with the same form of granules. Ventral 

 interradial plates bear somewhat prominent flattened fans of 

 minute spinules, webbed together at their base and showing three 

 to seven small points at the outer edge. Jaw-plates are raised 

 in the middle in the form of low verrucae, covered with uniform 

 and very small spinules. The peroral spines are slender, rather 

 longer than the adambulacral spines, and closely webbed to- 

 gether. The adambulacral spines are free only at the tips, the 

 web being continuous along the whole length of the groove. 



Off Florida; Bahamas; Jamica; West Indies generally; Colon 

 (coll. W. F. Bradley, Yale Mus., No. 758). 



