Yerrill, Notes on JRadiata. 291 



of the disk is thickly covered with similar spines, irregularly scat- 

 tered, except toward the outer part, where they have a tendency to 

 form radiating rows continuous with those on the rays. Minor pedi- 

 cellarige small, short and thick, thinly scattered among the spines on 

 the disk, hut becoming very numerous toward the end of the rays, 

 less so among the lateral and ventral spines. INIajor pedicellariai not 

 observed. Madreporic plate rather large, oval. 



Color, in alcohol, brownish black above, yellowish below. 



This species is closely allied to the preceding, but is quite different 

 in appearance. It may by distinguished by its relatively shorter 

 rays ; the much smaller and sharper spines of the upper surface, which 

 are much more numerous and scattered, and do not form three distinct 

 rows on the rays ; by the larger and more uniform lateral and ventral 

 spines, which are crowded toward the ambulacral furrows. 



Heliaster Cnmingii Gray. 



In a collection from Zorritos, Peru, Mr. Bradley has sent several 

 specimens of various sizes, which are, perhaps, the species described 

 by Gray. He also collected a few specimens at Paita. 

 . These resemble in form S. helianthus, but have exceedingly short 

 rays, ranging in number from 34 to 41. One of the largest specimens 

 measures from the center to end of rays 4'5 inches; to edge of disk 

 3 "8, the rays being mostly about half an inch in length. A smaller 

 one has a greater radius of 3-4 inches; lesser 2'8. The length of the 

 rays varies from one-eighth to less than one-tenth of the entire diam- 

 eter. The spines of the upper surface, also, are less numerous, and 

 much stouter, with more swollen tips, which are rounded and 

 capitate. They are arranged in a regular, simple, marginal row on 

 each side, and an irregular median series, sometimes forming a regular 

 double row, all the rows extending inward to near the center of the 

 disk, where they become irregularly scattered, but have nearly the 

 same form and size. The interambulacral spines form a single row, 

 one to each plate, and are mostly rather stout, with enlarged, blunt 

 tips. Outside of these, toward the edge of the disk, there is a row 

 of spines of about the same length, but stouter and more clavate, 

 and flattened at the ends. On the sides of the rays there are, in ad- 

 dition, two or three imperfect rows of similar, but shorter and more 

 flattened spines. 



Zorritos, and Paita, on rocks, at low-water, — F. H. Bradley. 



Under the name of Asterias {Heliaster) Cumingii Dr. Gray* very 

 briefly described a species, allied to or identical with this, as follows : 

 * Annals and Magazine of Natural History, 1st series, vol. vi, p. 180, 1840. 



