STARFISHES OF THE PHILIPPINE SEAS. 353 



often 3), becoming 1 near the end of ray. They are stout, flat, as long 

 or longer than extreme width of plate, round tipped or truncate, fre- 

 quently broader at tip than base, and smooth. The outer edge of 

 plate is bordered by 6 or more small pinched granules, which also 

 extend a variable distance along the transverse margins. A slender 

 slightly curved, 2-jawed, upright pedicellaria stands near the adoral, 

 inner corner of plate, with frequently a second smaller one a short 

 distance back of it, or sometimes near the outer adoral corner. 



Mouth plates with 14 to 18 furrow spines the adoral 4 heavy, the 

 rest decreasing very rapidly, the aboral being short. All the smaller 

 spinelets are slender, more or less flattened, and bent toward the 

 mouth angle. Subambulacral spines 5, the 2 series uniting at the 

 inner end and forming a horseshoe-shaped series for each mouth 

 angle. Outer end of mouth plates granular, with numerous pedicel- 

 lariae. as in Oreaster. 



Madreporic body large, roughly 4-sided (unsymmetrical lozenge 

 shape), flat, with numerous fine striae. It is at the edge of the apical 

 area, its outer end a little less than \ r from center. 



The color in alcohol is a very deep brown, almost black ; the speci- 

 men was bleached for photographing. 



Type.— Cat. No. 32632, U.S.N.M. 



Type-locality. — Tictauan Island, east of Zamboanga. Mindanao. 



Distrihution. — Known only from type-locality. 



Remarks. — Pentaceropsis tylodenna differs from P. obtusata^ in 

 having only 1 series of usually 2 (1 to 3) subambulacral spines (not 

 2 series of 3 to 4 each) ; slightly more numerous furrow spinelets 

 (8, in obtusata 5 to 7) ; in having larger triangular superomarginal 

 plates, without special tubercles (small, roundish, and with tubercles 

 in obtusata). In obtusata the abactinal plates which are convex are 

 more numerous and closer together, and the medioradial series is not 

 so clearly distinguishable as in tyloderrria. The photographic fig- 

 ures will give a better idea of the exact appearance of the creature. 



Nearly a year after the original description of P. tyloderma was 

 published I saw at the Museum d'Historie Naturelle 7 dried speci- 

 mens of P. obtusata from Mindoro (No. 247875). While I was not 

 able to make a direct comparison with tyloderma, even a hasty ex- 

 amination showed me that they belonged to a distinct species. Per- 

 rier's notes in the Eevision (p. 250) were based largely upon these 

 specimens. A few weeks later I saw 2 specimens of Pentaceropsis 

 at the British Museum. One, from Blanch Bay, New Britain (Willey 

 collection) is almost certainly not obtusata; neither does it appear 

 to agi'ee well with tyloderma.^ having very small superomarginals, 

 and also a quite different facies from the Paris specimens. A smaller 



1 Description by MllUer and Troschel, 1842, p. 50 ; Perrier, 1875, p. 250. 



