STARFISHES OF THE PHILIPPINE SEAS. 247 



Specimens examined. — Seven; 3 from type-locality and 4 from 

 the following stations: 



Station 5432, off Corandagos Island, east of northern Palawan 

 (lat. 10° 38' 45" X.; long. 120° 12' 45" E.), 51 fathoms, sand; 1 

 specimen. 



Station 5433. same locality', 54 fathoms, green mud, coral sand; 3 

 specimens. 



Remarks. — Rosastei' nannus is probably congeneric with DoHgona 

 con-finis Koehler, from the Andaman Islands, 67 fathoms (1910^, 

 p. 57), although nothing concerning the internal anatomy of the 

 latter is known. I have indicated the differences in the diagnosis. 

 R. nannus differs from R. l>ii)\(iiGtus (Sladen) in having larger abac- 

 tinal plates, which on the papular areas have peculiar and char- 

 acteristic marginal granules, longer marginal plates, much fewer fur- 

 row spines. In R. nannus 10 inferomarginals correspond to 32 adam- 

 bulacrals, while in N. bipunctus only 20 or 21 (according to figure). 



ROSASTER MAMILLATUS Fisher. 



Plate 5G, figs. 3, 4 ; plate 61, figs. 3, 4 ; plate 91, figs. 5, 5a.. 

 Rosasfer mamUlatus Fisher, 1913(7, p. 032. 



Diagnosis. — Differing from R. alexandri^ and other small species, in 

 having the superomarginals beyond the third plate separated by a 

 single series of abactinal plates nearly to extremity of ray, and in the 

 presence on the distal marginal plates of a small central tubercular 

 granule, larger than any of the other granules. R=21 mm., r=7.5 

 mm., R=a little less than 3 r; breadth of ray at midinterbrachium, 7 

 mm. Superomarginals massive, tumid, 13 in number, and covered 

 with roundish, rather coarse, subtruncate, slightly spaced granules, 

 the peripheral being largest on the dorsal facet of plate ; the 5 or 6 

 superomarginals preceding the last with an enlarged, subcentral, tu- 

 bercular granule ; inferomarginals corresponding to superomarginals, 

 tumid, the last 6 or 7 with a subcentral enlarged granule. Area of 

 abactinal plates stellate; median radial plates wider than long, sub- 

 hexagonal, the others subcircular, all tabulate; granules relatively 

 coarse, the peripheral flattened, finger-nail-shaped, 10 to 12 on the 

 radial plates and 8 to 10 on laterals; central granules roundish, low, 2 

 or 3 to G on radial plates, 1 to 3 on lateral plates; carinal plates of 

 attenuate part of ray small, tho.sc opposite the transverse sutures of 

 superomarginals elliptical or lozenge-shaped, the alternate plates 

 smaller and oblong ; abactinal plates with a few upright conspicuous 

 pedicellariae, with 2 oblong or slightly tapered jaws. Adambulacral 

 plates with a slightly curved furrow margin and 4 or 5 subequal, 

 slightly compressed, blunt, furrow spines ; subambulacral spines 3 or 

 4 in an oblique longitudinal seri'^s spaced from furrow, followed by 



