296 Verrill, Notes on Radiata. 



rows of about the same size, arranged alternately, Avith smaller mil- 

 iaries scattered among them. The three vippermost tubercles of both 

 the ambulacral and interambulacral systems are very small, and the 

 two next the last bear very small slender spines with globular, bright 

 purple tips. The ocular and genital plates bear each a somewhat lon- 

 o-er, slender spine. Abactinal system small, somewhat angular, de- 

 pressed, spines twice as long as the diameter of the test, rather stout, 

 with conspicuous verticillations, annulated ^A\\\ narrow bands of pur- 

 plish brown and light brown. 



Diameter of test -85 of an inch ; height -So. Cape St. Lucas, Lower 

 Cal.^ — J. Xantus. From the Smithsonian Institution, 



Astropyga venusta sp nov. 



Test circular, much depressed, nearly flat below, fragile, the ambu- 

 lacra considerably elevated above the general surface on the upper 

 side, Actinal area about one third the diameter of the test, its mem- 

 brane covered with unequal scales. Ambulacral zones about one 

 third as wide as interambulacral at the periphery, not varying much 

 in width to the actinal area, but tapering gradually to a point on the 

 upper surface where they are elevated and conspicuous. Pores in 

 arcs of three pairs, which are much more oblique above than below. 

 Ambulacral tubercles alternating in two rows, variable in size, largest 

 on the lower surface. Interambulacral tubercles in eight principal 

 rows, the four median not extending much above the outer curvature 

 of the margin, leaving a naked portion above. The tiibercles of the 

 external row are largest but extend only a little further toward the 

 center, with about three tubercles more. The row next to the exter- 

 nal has much smaller tubercles and extends to the summit. The 

 naked spaces radiate from the center and soon fork, one branch pass- 

 ing down between the second and third rows of tubercles along each 

 interambulacral border. These spaces are much depressed toward 

 the center and are light purple, with a row of dark purplish spots 

 extending to the end on each side, just within the second row of 

 tubercles, and terminating at the j^eriphery. The color of the lower 

 surface is light yellowish, extending upward in the center of each 

 interambulacrum in a broad petal-like space between the purple forks 

 of the naked area ; and in other narrower lobes, embracing the am- 

 bulacra and outer interambulacral tubercles, to the ocular plates. 

 Spines very slender and unequal in length, the longest about one half 

 the diameter of the test, finely barbed and longitudinally striated, 

 light flesh-color, or greenish with narrow bright purple bands. Ac- 

 tinal cuts not deep. Diameter 2'3 inches; of actinal area 'VS ; of 

 abactinal area '35 ; height of test about 'VS. 



