276 Verrill, JVotes on Radiata. 



Paita, Peru, — F. H. Bradley ; Dr. C, F. Winslow (Boston Soc. Natu- 

 ral History). 



Whether A. stellatus Gray, is identical with this species cannot be 

 determined by his very imperfect description, which applies equally 

 well to several other species. 



His description of A. stellatus is as follows : " Rays more than twice 

 the diameter of the body ; narrow central area of the rays equal to 

 one series of marginal tubercles. Coast of South America ?" 



Muller and Troschel place this, with doubt, as a synonym of A. 

 Valenciennesii M. and Tr., Vera Cruz. 



Patiria Obtusa Gray, Proc. Zoological Soo. London, 1847, p. 72. 



In the collection of Mr. Bradley* there is a specimen, which I refer 

 to this \ei-y imperfectly desci-ibed and hitherto obscure species. 



Greater radius '95 of an inch ; smaller '60. From pentagonal, with 

 regularly concave sides ; rays short, rapidly tapering and somewhat 

 obtuse at the end ; upper side convex. The ambulacral grooves are 

 deep and narrow, bordei*ed by rounded interambulacral plates, which 

 bear four or five long, rather slender spines in a single row, of which 

 the one next to the outermost is usually the longest, and the one 

 nearest the mouth considerably the shortest. Outside of these and 

 parallel with them is another row of spines of about the same num- 

 ber, form, and size, and borne upon plates of similar character, which 

 are connected with the inner row, and directly opposite to them. 

 The ventral plates of each triangular area, toward the mouth, bear 

 from four to six slender, sharp spines, a little shorter than those along 

 the ambulacral grooves, placed in a single transverse series on each 

 plate, or sometimes in a crescent-shaped group ; toward the margin 

 of the disk the plates and spines rapidly diminish in size, each plate 

 bearing three or four very small and slender spines, mostly placed 

 transversely side by side. The margin is formed by a row of small 

 rounded plates, without a sharp edge, and closely covered with minute 

 granule-like spines. The dorsal surface, near the margin between the 

 rays, is covered with small, close, uniform plates, which bear closely 

 crowded, circular or rhomboidal clusters of minute papilla-like spines, 

 which are subdivided at the end into microscopic radiating points. 

 The plates increase in size toward the central area, and at a short 

 distance from the margin become crescent-shaped and separated by 

 the dorsal pores, with other much smaller rounded plates between 

 them, each of which bears a small rounded cluster of small spines, 

 silmilar to those borne by the larger plates, which are longer toward 



* The locality is uncertain, probably Panama, but perhaps Paita, — Reprint. 



