Verrill, Notes on Raduita. 273 



height of broadest upper plates -1, length -07 ; length of longest mar- 

 ginal spines '15. 



Panama, at extreme loAV-water on sand, and Zorritos, Peru, — F. H. 

 Bradley. 



A specimen measuring 1-3 inelies from center to tip of rays agrees 

 closely with the preceding description, except in lacking the small 

 tubercles on all the upj)er plates, even at the base of the rays. It 

 has 30 marginal plates. 



This species is, in many respects, allied to A. regcdis Gray, of which 

 I add a description for comparison, but is nevertheless remarkably 

 distinct in form and many other miportant characters. 



Astropecten regalis Gray, Ann. and Mag. N:it. Hi.st, vi. p. 178, 1840. 



A depressed species with broad, short arms, a little contracted at 

 base, scarcely acute. Eadius of rays to that of disk at 3 : 1. A speci- 

 men I'o inches from center to tip of rays, has 23 marginal plates. 



The interambulacral plates bear three slender spines at the inner 

 edge, of which the central is nearly twice as long as the others, and 

 outside of these a single, sharp, much stouter, but scarcely longer, 

 spine. The lower marginal jilates are closely covered with even, flat- 

 topped granulations, and bear along the outward border from 5 to 8 

 nearly equal, small, conical spines, and at the upper margin, usually, 

 two large, flattened, blunt or lanceolate spines, which are largest 

 toward the base of the rays, but quite small in the interradial region. 

 They are mostly channeled upon the upper side and convex beneath. 

 The upper marginal plates are low and rather short, closely covered 

 with unequal rounded granules, those upon the middle being largest 

 and, on the plates toward the tip of the ray, enlarging into small 

 rounded tubercles, two, three, or four standing in a transverse row 

 along the middle of the plate. The plates on the basal portion of the 

 ray are destitute of tubercles or spines, in both of my specimens, but 

 older specimens may, perhaps, attain small tubercles even to the base 

 of the ray, since there are fewer on the younger specimen. The dor- 

 sal area of the rays is broad, with fine paxilUe. The lower marginal 

 plates project considerably beyond the upper. 



The larger specimen is 1*5 inches from center to tip of ray ; "48 to 

 edge of disk; width of ray at base '5, of dorsal area "3 ; length of 

 longest marginal spines "18. 



Panama,— F. H. Bradley ; San Salvador,— Capt. J, M. Dow (Coll. 

 Smiths. Institution). 



It is quite probable that the Astropecten ccelacanthus Martens,* 



* Monatsb der Akad. der Wi<s., Berlin, Jan., 18G5, and translated in Annals and 

 Mag. Nat. History, vol. xv, p. 435, 1865. 



