290 Verrill, Notes on Radiata. 



three rows of spines, which are crowded and rather indistinct, decreas- 

 ing in length outwardly from the ambulacral grooves, those of the 

 first row being of about the same size and shape as the interambula- 

 cral. Beyond these on the sides of the rays there are three, more 

 distant, regular, longitudinal rows of short spines, those of the two 

 lowest being conical and somewhat sharp ; those of the upper flat- 

 tened, and blunt, or dilated at the ends. On the dorsal side, each ray 

 has a crowded, irregular, broad, median belt or row, and a more 

 simple, crowded, marginal row on each side, all of which extend to 

 the central area of the disk, where the spines become very numerous 

 and irregularly crowded. All the spines of the upper surface are 

 short and thick, with enlarged, rounded tips. Numerous, very small, 

 short, pointed pedicellarine are scattered over the surface between the 

 spines, and beneath, among the lateral and ventral spines, there are 

 other much larger ones, which are short, broad-oval, with pointed 

 tips. Madreporic plate small, inconspicuous, irregular. 



Color, in life, dark greenish brown, the spines reddish, yellowish, or 

 light green. 



Heliaster microbrachia Xantus, Proc. Phil. Acad Nat. Sci., I860, p. 568. 



A few specimens that appear to be identical with this species were 

 collected by Mr. Bradley at Panama and the Pearl Islands, on rocks 

 at low-water, and in cavities higher up. The original specimens of 

 Mr. Xantus were obtained at Cape St. Lucas. 



Disk very broad, rays relatively shorter than in the preceding, 

 small, slender, about thirty in number. Radii about as 3 : 2. A me- 

 dium-sized specimen measures from center to end of rays 2*8 inches; 

 from center to edge of disk 2 ; the free part of the rays varies in 

 length from "5 to 1 inch. 



The interambulacral plates bear a single row of slender, blunt 

 spines, which are quite long toward the mouth, but shorter than in 

 preceding species on the free part of the rays ; small spines frequently 

 alternate with the larger ones. Outside of these along the lower and 

 lateral sides of the rays there are about four regular longitudinal rows 

 of longer and stouter spines, not clearly distinguishable into ventral 

 and lateral, but those of the upper rows are more flattened and clavate 

 at the ends. The dorsal side of the rays is covered with numerous, 

 small, slender, sub-acute, nearly equal spines, arranged along each 

 margin in a distinct row, which extends inward on the disk, but not 

 forming a distinct median row, the surface between the marginal rows 

 being nearly evenly covered with the spines, among which indications 

 of five or six indistinct rows may, sometimes, be traced. The surface 



