284 Verrill, N'otes on Radiata. 



Goniodisc-us Stella Verrm, sp. nov * 



Form pentagonal, with short, acnte rays, and regularly concave 

 sides. Radius of rays to that of disk as 8:6. Marginal plates, in a 

 specimen one half inch from center to end of rays, five on each side 

 of rays, those above and below corresponding. These plates are 

 squarish, about as broad as long, diminishing regularly to the tips of 

 the rays. The interambulacral plates bear each three or four short 

 spines of which the central one is slightly longer and larger ; these 

 form a single range along the groove. Outside of these there is a row 

 of slightly longer and much stouter, flattened, oval, blunt spines, which 

 do not reach the end of the rays. The ventral plates are closely 

 granulated, those nearest the margin bearing one and sometimes two 

 small rounded tubercles on the center. The marginal plates, above 

 and below, are closely and finely granulated ; the two of the lower 

 series, next the end of the rays, bear each a small rounded tubercle. 

 The dorsal surface is covered by very regular hexagonal plates, 

 which are covered by rounded, unequal granulations, coarser and less 

 crowded than those of the margin. These plates are nearly flat and 

 each is surrounded by six pores, placed at the angles, except a few of 

 those opposite the angle between the rays, which lack a part of the 

 pores. The central area is surrounded by five somewhat larger plates, 

 corresponding with the interradial spaces, and by five others a little 

 more prominent outside of these, alternating 'with them and corres- 

 ponding with the rays, which have, along the centi'al line, a row of 

 plates that are a little more prominent, but not appi'eciably larger than 

 those of the general surface. The anus is central, surrounded by fine 

 irregular plates. Color, in alcohol, grayish yellow. 



The only specimen seen, which is probably young, is •48 inch from 

 center to end of rays ; '3 to edge of disk ; length of largest marginal 

 plates 'OS ; diameter of medium sized dorsal plates "05 of an inch. 



Cape St. Lucas, Cal., — J. Xantus (Coll. Smithsonian Institution). 



Since the above has been put in type, another large specimen has 

 been sent us from Zorritos, Peru, by Mr. Bradley, agreeing in most of 

 its features with the one described, but having characters that cause 

 it to approach NidorelUa armata. This specimen, therefore, leads 

 me to suspect that both may, possibly, prove to be the young of the 

 latter. 



The Zorritos example measures, from the center to end of rays, "72 ; 

 to edge of disk '48. Six plates on the sides of the rays, above and 

 below. Most of the ventral plates bear a small rounded tubercle; 

 the larger spines of the row outside the ambulacral grooves are stout, 



* This has since been ascertained to be the young of the preceding species, — Reprint 



