STARFISHES OF THE PHILIPPINE SI1A.S. 101 



Superoniarginal plates, 33 or 34 to a ray, are massive and con- 

 fined to side of disk in interbrachia, but the upper end soon widens, 

 and the plates become lower, so that the lateral face about equals 

 the dorsal, there being no sharp angle between the two for the plates 

 form a rounded edge to the ray. The lateral face of the supero- 

 marginals is not vertical but sloping so that outside of the inter- 

 brachia the whole width of the plate can be seen when view^ed from 

 above. All except the last 5 to 10 plates bear a stout, flattened, 

 sharp spine equal in length to 1.5 or 2 plates. In the interbrachia 

 this is situated at the extreme upper end of the plate, and gradually 

 recedes from the inner edge as the width of the dorsal face in- 

 creases, keeping on the rounded angle between the latter and the 

 lateral face. This spine is bent toward the end of the ray and 

 usually appressed, except in interbrachia. The surface of the plate 

 is covered witfi flat, large, squamiform granules with a polygonal 

 or broadly leaf-shaped contour, the free edge turned upward on the 

 lateral face of plate and distad on the dorsal, where the granules 

 are largest. These are transformed into pulpy spatulate spinelets 

 on the edge of the plate and finally in the narrow abrupt fasciolar 

 grooves they become capillary. The base of the spine is surrounded 

 by a small bare space, except at the base of the ray, but it is less 

 extensive than in Psilater agassizL 



Terminal plate about as long as wide, with a notch on the prox- 

 imal border, and with 3 stout sharp terminal spines, 1 dorsal and 

 2 lateral. 



Inferomarginal plates confined to side wall of ray, except on outer 

 fourth, forming a steeply sloping wall, their upper end projecting 

 slightl}^ laterally beyond the superomarginals. Except the first 3 

 plates, they are one-third to one-half higher than the superomar- 

 ginals to which they correspond exactly. The first and sometimes 

 the second plate bears at the lower end a single flattened sharp 

 appressed spine pointed upward. The others, except the last 5 or 

 10 plates (which also have only the lower spine) have 2 such ap- 

 pressed spines, one near the upper and one near the lower end, and, 

 proximally, near the median line but soon moving to the distal 

 margin. These spines are very robust, the upper being about as 

 long as the height of plate and the lower about three-fourths as 

 large. The granules covering the plate are very flat and squami- 

 form, broadly leafshaped and directed upward. On the median 

 transverse area of the plate they are rather sparse, but there is no 

 well-defined naked area. These squamiform papillae are invested 

 with membrane like the superoniarginal squamules but are not so 

 pulpy as the actinal spinelets. 



13434— Bull. 100—19 8 



