290 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Mouth plates large with the furrow margin about twice as long 

 as that adjacent to first adambulacral plate. Furrow series: 15 to 

 17 compressed chisel-pointed spines, the inner 3 or 4 gradually 

 enlarged and prismatic, the innermost being widest, and blade- 

 like. Actinal surface with about 3 series of granules parallel to the 

 furrow, a pair just back of the teeth enlarged into prismatic spines; 

 median suture rather prominent; actinal surface of plates slightly 

 convex. 



Madreporic body rather small, surrounded by 6 plates, and situ- 

 ated one-third r from center. 



The gonads are single, one on either side of the membranous inter- 

 brachial septum, situated between the third and fourth longitudinal 

 series of radial plates and about 6 mm. from the margin. No rudi- 

 mentary superambulacral ossicles. 

 Type.— C?ii. No. 30553, U.S.N.M. 



Type-locality. — Station 5425, Sulu Sea, near Cagayan Island, 495 

 fathoms, gray mud, coral sand, bottom temperature 49.4° F. ; 1 

 specimen. 



Distribution. — Known only from type-locality. 

 Remarks. — Although this species is very different from 8. hourgeti 

 and S. ammophilus in having narrow superomarginals and larger 

 adambulacral plates with numerous furrow spines, I think it is 

 referable to Sphaeriocliscns. The abactinal plating, marginal granu- 

 lation, and slightly enlarged antepenultimate superomarginal are 

 characteristic. I have examined the gonads and abactinal plates of 

 8. ammophilus and they agree with those of S. scotocrypfus. In the 

 former the plates of the very restricted papular areas are 4- to 6- 

 lobed, the lobes being short, sharply truncate, and joining closely 

 end to end the lobes of adjacent plates. In the radial series the 

 lateral lobes (2 on either side) are developed more fully than the 

 other 2, which may be lacking. The form of the lobing is exactly 

 similar to that of S. ammophilus., even to the larger lateral lobes. 

 It would seem that the very small papular areas are also character- 

 istic of the genus. S. ammophilus has single gonads, situated as in 

 S. scotocryptus. 



Genus PELTASTER Verrill. 



Peltaster Verbill, 1S09, p. 1G8. Type P. hebes Verrill i=Oonia8ter nidaro- 

 siensis Storm), — Fisher 1911(f, p. 171. 



PELTASTER CYCLOPLAX Fisher. 



Plate 74,* fig. 1 ; plate 75 ; plate 83, fig. 1 ; plate 92, figs. 11, llor-d. 

 Peltaster cycloplax Fisher, 1913a, p. 641. 



Diagnosis. — Differing from P. nidarosiensis (Storm) in having 

 entrenched, 2-jawed, pincer-shaped or " sugar-tongs " pedicellariae 



