258 NEW STARFISHES AND OPHIURANS—VEBBILL. 



granulated, without spines, and have diifereutiated marginal granules 

 along the sutures, forming narrow fascioles. The abactinal ossicles are 

 mostly i^arapaxilhe, regularly arranged in several longitudinal rows 

 along the middle of the rays, with tlie central row clearly defined; 

 they are closely and evenly covered with angular granules, those 

 around the edge diifereutiated. The papulae are restricted to the 

 central part of the disk and the baso median part of the rays. 



The actinal interradial areas are large aud covered with many more 

 or less rhombic plates closely arranged in regular rows parallel with 

 the ambulacral grooves. The plates are covered with even granules 

 similar to those of the upper surface. 



Some of the actinal plates usually, but not in all specimens, bear 

 small valvate pedicellaria", usually with two or three valves, similar in 

 size to the granules; similar pedicellarije may occur in small numbers 

 on the marginal and abactinal plates. 



The armature of the adambulacral plates is in longitudinal rows, 

 usually three rows to a plate. 



The jaws are not prominent ou the actinal side; they have marginal 

 and actinal rows of spines. The ambulacral feet have terminal suckers. 



This genus differs from NympliasUr chiefly in having broad abactinal 

 areas ou the rays. From Paragonaster it differs in that character and 

 also in having the actinal plates evenly granulated, and the furrow- 

 spines in a straight row. 



The pavement-like arrangement of the actinal plates, the granulation 

 of the plates, and other characters indicate that it belongs to the family 

 Pentagouasterida% as limited bySladeu. 



ISASTER BAIEDII, V e r r i 1 1 . 

 Archaster bairdii, Verrill, Amer. Journ. Sci., xxiii, p. 139, 1882. 



Disk broad, flattened, or moderately convex, with the interradial 

 margins broadly curved, and the edge evenly rounded, owing to the 

 faint elevation of the upper marginal plates. Rays broad at base, 

 rapidly tapered to rather slender tips. Lesser to the larger radius 

 about as 1 to 2.5. Lesser radius of one of the largest specimens, 23 mm. ; 

 greater radius, 54 to 56 mm. Another specimen has the lesser radius 

 18 mm.; greater, 53 mm. 



Abactinal area of the disk and rays closely covered with rather large 

 crowded parapaxilhe, which are round or polygonal according to the 

 amount of crowding, with a median row along the rays slightl}' larger 

 than the others. The parapaxilhe consist of a round, convex, cylin- 

 drical or slightly clavate column, arising from the center of each of the 

 plates. On the middle region of the basal portion of the rays, the 

 plates are united by more or less stellate })rocesses so as to leave large 

 intervening pores for the papulae; but in the triangular interradial 

 areas the plates are closely united, without pores between them. On 

 these areas they become protoi)axilhe, and are closely crowded in rows 



