STARFISHES OF THE PHILIPPINE SEAS. 469 



scattered spiraeula, and that between the fans has numerous spiracula 

 in short irregular lines. The supradorsal membrane is dotted with 

 numerous very small whitish spots of unequal size, due probably to 

 groups of gland cells. There are rather large, well-spaced, brownish 

 rings or spots on the outer half of R. 



Ambulacral furrow wide; tube feet, with small disks, in 4 longi- 

 tudinal series. Adambulacral plates of two sorts, prominent and non- 

 prominent. The former project farther into furrow and bear an 

 oblique transverse series of 3 or 4 slender spines invested in mem- 

 brane which forms a small sacculus at tip. The outer spine is the 

 longest (equals the length of 5 plates at base of furrow), the other 

 two decreasing slightly in length. The innermost often projects be- 

 tween 2 feet of the outermost series and is deeper in the furrow than 

 the outer. The nonprominent plate corresponds to a tube foot of the 

 outermost series, is set back slightly, and bears only 1 spine, which 

 stands in the same longitudinal series (with reference to long axis of 

 ray) with the outermost spine of the prominent plates, and is of 

 about the same length as this spine. Aperture papillae short, broadly 

 ovate, with a membranous envelope produced into a short, blunt sac- 

 culus. The calcareous part is only about one- fourth the length of the 

 adjacent subambulacral spine, and there is no difference between the 

 papillae of the two sorts of plates. The apertures are narrow and not 

 completely covered by the papillae. The first adambulacral plate, 

 sometimes prominent, sometimes nonprominent, has 2 equal or 

 unequal spines and a large aperture papilla immersed in the actino- 

 lateral membrane. 



Mouth plates small and very high, the combined pair produced 

 actinally into a conical eminence, the apex of which is situated at 

 the middle of the median suture. The height of this extraordinary 

 beak or cone equals the interradial diameter of the pair of plates. 

 From the blunt point at the top the plates slope straight and steeply 

 to the actinostomial margin, which is produced into a slight beak, 

 but in the opposite direction the plates diverge, leaving an open 

 suture, and the margin of the plates is arcuate and nearly perpen- 

 dicular. Marginal spines 3 or 4 (sometimes only 2), the lateral-most 

 usually the strongest and longest, situated on a slight angle of the 

 margin and directed across mouth of furrow. The innermost spine 

 which is well spaced from the median beak of actinostomial margin is 

 nearly as long as the lateral-most and the 1 or 2 intermediate spines 

 are somewhat shorter. Suborals 2, nearly like the subambulacrals 

 and situated in a line parallel to and near median suture, on the 

 actinostomial face of the cone. 



Actinolateral membrane translucent forming a broad margin which 

 decreases in width evenly from interradial angle. The fourteenth 

 spine is the longest, and is the first to meet the free edge of mem- 

 13434— Bull. 100—19 31 



