394 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



pedicellariae, papulae, and general appearance indicate that this 

 specimen is O. tuberifer or at most a variety. The papular areas 

 are large and in 6 longitudinal series with upward of 18 pores to an 

 area on the disk, and 15 on the ray, the number decreasing toward 

 the end of ray. 



The abundant pedicellariae would readily distinguish this speci- 

 men from 0. ornatus Koehler, to which the granules between the 

 subambulacral spines would suggest an alliance. The biseriate and 

 generally irregular character of most of the adambulacral armature 

 does not at all conform to the triseriate separated armature of 

 omotus. This specimen is certainly not normal. 



Type. — In the British Museum. 



Type-locality. — Challenger station 186, Torres Strait, off Cape 

 York, 8 fathoms, coral mud. 



Distribution. — Torres Strait; Andaman Islands, 53 fathoms 

 (Koehler) ; Thursday Island (Doderlein) ; Sulu Archipelago. 



Specimens examined. — Two : 



Station 5153, off Tocanhi Point, Tawi Tawi Group, Sulu Archi- 

 pelago, 49 fathoms, coral sand, shells. 



Station 5147, 8.4 miles southwest of Sulade Island (near Jolo), 

 Sulu Archipelago, 21 fathoms, coral sand, shells. 



OPHIDIASTER DUBIOSUS (Koehler). 



Plate 110, fig. 2 ; plate 111, fig. 4. 

 LincJcia duMosu Koehler, 1910a, p. 155, pi. 18, fig. 10, 11. 



Notes on Philippine specimen. — In the possession of a few excavate 

 slender pedicellariae, this specimen differs from the type. The abac- 

 tinal plates are a trifle more convex, and, as noted in the description 

 beloAV, there is present a rudimentary subambulacral spine or granule 

 near the tip of ray. Otherwise the specimen agrees very well with 

 the description given by Koehler. To be sure the madreporic body 

 is subtriangular, but that is always subject to considerable variation 

 in this genus. 



The species may be characterized as resembling 0. sclerodermus 

 Fisher and O. tenellus Fisher, but with more tumid and more regu- 

 larl)'^ arranged abactinal and marginal plates, few or no pedicellariae, 

 and no subambulacral spines, except in a rudimentary state at end 

 of ray. 



The following is a description of the specimen : 



R=55 mm., r=7.5 mm., E=7.3 r; breadth of ray at base, 8 to 8.5 

 mm. Plates arranged in very regular longitudinal and transverse 

 series. Abactinal and marginal plates roughly shield-shaped, nearly 

 equal, separated b}^ very regular series of papular areas, 6 in all. 

 Plates evenly convex, the sulcuses separating the longitudinal rows 



