178 NATURAL HISTORY BULLETIN 



as long, slightly convex, separated by a groove, spineless, and 

 covered nearly uniformly and closely with small hemispherical 

 granules, becoming spinuliform in the sutural grooves. 



Dorsal paxillge are pretty fine, close, and form transverse series 

 laterally, but are irregular on the median third of the ray and 

 on the disk. Those of the rays have three or four central gran- 

 ules, or short spinules, and eight to ten marginal ones. On the 

 disk the paxilliform marginal spinules are much more numerous 

 and finer than the central ones, which may be ten to twelve, so 

 that their outlines are well defined by this inequality. 



The inferomarginals have two large upper spines, up to 4°'°' 

 long, cylindric or flattened, not tapered, mth a smaller spine 

 at their bases. Their sutural grooves are bordered with regular 

 spinules, near which is a regular row of six or seven spaced, 

 elongated, slender, pointed spinules, arising frorii small notches 

 in the plate. The spines are longer distally. There are also 

 similar spinules on the free border and on the border next the 

 adambulacrals. (Condensed from Perrier.) 



The adambulacral plates have an inner marginal row of three 

 divergent spines, the middle one longest ; the actinal surface has 

 two larger spines, one behind the other, the outer one often 

 smaller or replaced by several spinules. 



The type was from Cayenne, French Guiana. This appears to 

 be very closely allied to A. articulatus, var. dubius. I have not 

 seen the type. 



ASTROPECTEN CINGULATUS Sladcn. 



Astropecten dngulatus Sladen, Voy. Challenger, Zoology, vol. xxx, p. 218; 

 pi. XXXV, figs. 5, 6; pi. xxxix, figs. 1-3 (enlarged, details), 1889. 



The rays are unusually short, with about 19 broad marginal 

 plates, wider than high. The type had the radii 9°^^ and 28^™ ; 

 ratio, 1 :3.1. 



The superomarginal plates are large and broad, at middle of 

 ray wider than the narrow paxillar area. They therefore form 

 a wide border to the rays ; surface closely granulose. 



The inferomarginal plates have two short, nearly terete, slen- 

 der acute equal spines, with smaller acute spines at their bases 

 and an aboral series of small acute spines beneath. The under 

 side is covered with small, short, appressed spinules. 



