WEST INDIAN STARFISHES 181 



AsTROPECTEN ALLIGATOR Perrier. 



Astropecten alligator Perrier, op. cit., 1881b, p. 30 j Etoiles de Mer, p. 270, 

 1884. 



According to Perrier the essential characters of the type are 

 as follows: 



Radii 9°^™ and 40°^ ; ratio, 1 :4.5 ; breadth of ray at base, 9^°". 

 Superomarginal plates are thirty on each side of a ray. 



The disk and rays are flat; rays acute. The inferomarginal 

 plates project laterally beyond the upper ones. 



The superomarginal plates are little elevated, almost square; 

 interradial ones broader than long. They are covered with pret- 

 ty coarse, prominent, spaced granules. Three or four proximal 

 plates bear each a single, pretty short, conical spine, on the 

 middle of the interior border ; that on the triangular first plate 

 is largest ; those farther out become nearer to the exterior side. 



The inferomarginal plates have two flat and acute marginal 

 spines; underneath they have a row of about three smaller flat 

 spines along the aboral margin; the rest of the surface is cov- 

 ered with acute scale-like spinules, among which are some larger 

 obtuse, flat spinules. 



The adambulacral plates have a furrow-series of three diver- 

 gent spines; one or two smaller ones are placed on the lateral 

 margins, and three on its exterior margin. Sometimes there is 

 also a central spine on the plate. 



The paxillar area, at the base of the rays, is about equal to four 

 times the breadth of the marginals. The paxillae are small ; they 

 have six to eight slightly clavate spinules surrounding a group 

 of central ones. They form pretty evident transverse rows cf 

 about fifteen, proximally, on the rays. Off Alligator Key, Flori- 

 da, in 147 fathoms.2^ I have not studied the type. 



Astropecten nuttingi Verrill, sp. nov. 

 Plate xii ; figures 2-2e. Details. Plate xxi ; figures 1-2. Type. 



A regularly stellate species, rather thin vertically. The disk 

 is usually rather flat, and often has a central conical elevation. 



26 Perrier (1884) gave the depth as 147 feet. There is no such depth 

 given in the original lists of dredgings off Alligator Keef, but there is one 

 of 147 fathoms (No. 194 P). Probably there was an error in transcribing 

 the label. 



