154 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Remarks. — The specimens probably are all immature, although 

 the type has the gonads developed, making the generic determination 

 certain. The examples from station 5445 are small, and, owing to the 

 lack of development of the papulae and the low paxillae, resemble 

 narrow-rayed Patagiaster. It would be difficult to distinguish the 

 young of these 2 genera, since the distinction depends upon the dis- 

 tribution of gonads and papulae. 



This species is similar to D. sladeni in general habit, but the 

 paxillae are composed of thorny clavate spinelets which can not 

 by any stretch of the imagination be called " capillary." They are 

 stouter in proportion to length than in any other oriental species. 

 The marginal spines are not so well developed, and even though the 

 specimens are small the adambulacral plates have 8 or 9 furrow 

 spines and upward of 20 subambulacral spinules. The madreporic 

 body is rather small. 



Gemis PATAGIASTER Fisher. 



Patagiaster Fishee, 1906, p. 1029. Type, P. nuttingi Fisher. 



PATAGIASTER SPHAERIOPLAX Fisher. 



Plate 28, fig. 3 ; plate 29, fig. 3 ; plate 41, figs. 4, 4a. 

 Patagiaster sphaerioplax Fishee, 1913a, p. 623. 



Diagnosis. — Differing from P. nuttingi in having shorter, broader 

 rays, larger paxillae with more numerous granules; in having the 

 paxillae in a definite radial, and parallel longitudinal series: in 

 having broader marginal plates and slenderer actinal spinulation. 

 E=28 mm., K=12 mm., K=2.3 r; breadth of ray at base, 13.5 mm. 

 Disk large, rays short, tapering from wide, rounded interbrachia to 

 a pointed extremity ; general form depressed ; sides of ray rather thin, 

 rounded. 



Description. — Paxillar area very compact, the paxillae crowded 

 and large. The smallest paxillae are on the central portion of disk, 

 in a circle with a radius of about one-half r; they increase rapidly 

 in size and are largest on the peripheral interradial regions and 

 proximal radial areas, decreasing slightly in size toward the end of 

 ray. A regular radial series is clearly discernible, the others being 

 arranged parallel to this, as in Pseudarchaster and many other 

 Goniasteridae. In a transverse line across the base of the ray 13 to 

 15 of these series can be counted. Three series reach the end of the 

 ra}'. The larger paxillae have a convex flaring crown with about 

 30 to 40 elongate regular beadlike granules, surrounded by a periph- 

 eral series of numerous, slender, short sf)inelets, some of which are in- 

 termediate in form with the central granules. As compared with 

 P. nuttingi, the paxillae of sphaerioplax are larger, not only com- 

 paratively but actually, especially on the rays, and there is a smaller 



