STARFISHES OP THE PHILIPPINE SEAS. 307 



radial regions, as well as all the plates immediately adjacent to the 

 siiperomarginals (including 4 or 5 distal median radial plates) are 

 distinctly tumid either in the middle or over the whole surface. 

 Three of the above-mentioned interradial plates nearest center of 

 disk have the convexity in the form of a low mamelon in the middle 

 of the plate. A circle of 10 plates, including the 5 primary basals 

 (the largest plates), encloses a stellate area comprising a central 

 and 5 " inf rabasal " plates with a small extra plate between 2 infra- 

 basals. Outside the circle of basals and " infraradials " is a very 

 regular circle comprising 15 plates — 5 pairs of large subhexagonal 

 plates abutting against the still larger basals and each with a low 

 central convexity. Between each pair is the broadly oval primary 

 radial plate, from which proceeds a very regular series of 8 or 9 

 radial plates, that adjacent to the primary radial being abruptly 

 smaller, the rest increasing in size distally. These and a parallel 

 similar adradial series are margined by subtruncate finger-nail- 

 shaped granules which are set slightly below the general level of 

 the plates, and which arch over conspicuous intervals between the 

 plates, and hide the papulae beneath. The other plates are bor- 

 dered by smaller, very narrow, elongate granules, with a straight 

 outer edge and set a trifle below the level of the surface, for all the 

 plates are very slightly swollen, although the general surface may 

 be plane. The plates of the radial areas, including the midradial 

 and 2 series on each side, are the smallest and have the largest 

 peripheral granules. The papulae are distributed all over the disk, 

 except 1 chevron of large interradial plates. 



The plates of the radial areas are 6-lobed, the 2 lateral lobes of 

 each side being the most prominent, bent slightly downward and 

 overlapping a trifle the lobes of adjacent plates. The distal and 

 proximal lobe is really only incipient, truncate, and tightly joined, 

 end to end, with the next plates. Coelomic surface plane or slightly 

 concave, not convex, as in Lithosoma. 



Sujoeromarginals 7 or 8 to the ray, very massive, conspicuously 

 elevated or tabulate, with an uneven surface much as in Astro- 

 ceramus sphaeriosiictus^ the interval between the plates being a 

 rather deep sulcus. A similar sulcus follows the midradial line, 

 as the third superomarginal meets its fellow medially, and the re- 

 mainder of ray is composed of superomarginals only. Seen from 

 above, the first 2 plates are slightly wider than long and nearly of 

 a size, but from this point they gradually, but rather rapidly, de- 

 crease in size, the outer plates being a trifle longer than wide or 

 the 2 dimensions equal. Despite the unevenncss of the plate, sug- 

 gesting strongly the condition of AfitroceraTnns s phaer lost ictus ^ 

 there are no granules such as are present in that species, but there 



