Verrill, Notes on Radiata. 571 



Echinaster tenuispina Verriii, sp. nov. 



Kadii about as 1:5-8. Rays five, rounded, long, moderately stout, 

 tapering to the end. Spines of the dorsal surface small, but very 

 numerous, tapering, subacute, arranged in many scarcely defined 

 rows, of which there appear to be about 16 on the rays. The inter- 

 ambulacral plates bear numerous, crowded, divergent spines, of about 

 the same size and form as those of the dorsal surface, those of the 

 opposite sides crossing ; three of these arise from each plate, in a 

 transvei-se row; the middle one is considerably largest and longest, 

 the outer one somewhat shorter and blunter, the inner one much 

 smaller, slender and acute. The skin is smooth and glossy ; in the 

 angles between the i"ays beneath and along the lower side of the rays 

 there are numerous slender transvei-se furrows. 



Radius of disk -60 of an inch; of rays 3-50; wddth of rays at base 

 •62 ; length of largest spines '06. 



Color of dried specimens deep reddish brown. 



La Paz, — Capt. J. Pedersen. Six specimens. 



This species is allied to M spinulosus V., from the west coast of 

 Florida. Its rays ai'e not so slender and the dorsal spines are still 

 more numerous. 



Ophidiaster pyramidatus Gray, (p. 287). 



Several specimens were sent from La Paz by Capt. Pedersen. 



The dry specimens in best condition are light straw-color beneath; 

 the poriferous zones are bright orange; the rows of large plates on 

 the back and sides olive-green ; madreporic plate large, dark olive- 

 green. 



Lepidaster, gen- nov. 



Disk small, rays rounded, elongated ; whole surface covered with 

 a thin smooth skin, without granules or spines. The skeleton consists, 

 in the rays, of several similar dorsal and lateral rows of rather large, 

 more or less rhomboidal, overlapping plates, so articulated with 

 those of the adjacent row^s as to leave a regular row of pores between 

 all the rows of i)lates, except between the ventral and interambulacral 

 rows. On disk the plates are pentagonal. The interambulacral 

 plates bear an inner row^ of small slender spines, several to each plate, 

 bordering the ambulacral groove, and outside, but adjacent to these, 

 a row of much larger oblong spines, not more than one to a plate. 



This genus is allied to Tamnria and Cistina of Gray, but in both 

 of those groups the plates bear spines. Ophidhister and Linckia are 

 granulated and the plates are arranged quite differently. 



