regions 



94 

 not separated. The whole surface is not granular, but everywhere punctate, with some 

 larger pits symmetrically distributed. Front somewhat defle.xed, resembling that of Pt. barbatiis 

 and Pt. pusi/lus, but the anterior margin is still more sinuous (fig. 6a), with the median lobes 

 broader and more prominent, and a single, but rather thick row of granules'), 

 lookino- as if it consists of two entirely contiguous rows; lateral lobes subrectangular, obtuse; 

 the width of the front, as Miss Rathbun remarks, is half the greatest breadth of the carapace, 

 lying between the tips of the first or second pair of epibranchial teeth. Upper orbital margin 

 slightly oblique, granular, without fissure marking the transition to lateral margin of the front. 

 External orbital angles slightly prominent, acute, with the lateral margins (that are as long as 

 those of the following teeth) diverging backward and ending posterioriy in a triangular, distinct 

 sinus; anterior epibranchial teeth somewhat pointed, lateral margins subparallel, followed at 

 either side of the carapace by a very minute tooth, behind which the lateral margins are 

 converging backward. 



Bases of antennules separated by a very broadly-triangular nasal lobe; epistome very 

 short, almost linear, crenulate at posterior margin ; inner suborbital lobe obtusely-triangular ; 

 peduncles of antennae contiguous to, but not coalesced with, the lateral angles of the front. 



Miss Rathbun already states, that the e.xognath of the e.xternal ma.xillipeds is somewhat 

 broader than the ischium, more so in the cf than in the 9,; the ischium does not increase in 

 width towards it anterior margin, and the auricle of the merus is very large (fig. 6c). 



The chelipeds of the cf are equal in size and unusually stout and bulky. Arm unarmed, 

 granular at outer surface, and hairy along upper and inner edge. Wrist flattened above, with 

 inner margin somewhat sharpened and bent rectangularly towards the palmar joint. Palm much 

 inflated; length of chela equal to distance between external orbital angles; fixed finger straight, 

 with five teeth at the cutting margin : two very small ones near the somewhat spooned extremity, 

 preceded by two much larger, conical ones and one smaller tooth; movable finger much curved, 

 so that a wide gap is left between the bases of the fingers, cutting margin irregularly crenulate, 

 but none of the teeth attaining the size of the two large ones on the opposite finger; palm 

 higher than Jong, smooth, but marked on the outer surface with numerous white patches, that 

 are narrower and longitudinally disposed near the superior border, which is rounded, not keeled. 

 The gap between the fingers is filled at the outer surface by a thick 

 patch of hairs, as occurs in many other species of Ptychognathus\ these hairs extend 

 halfway on the fingers (fig. db). 



The walking legs are nearly hairless, only some hairs being observed at the posterior 

 border of the slightly flattened propodites and on the dactyli. Meropodttes unarmed, with a 

 subdistal rectangular prominence at anterior margin, and 37. times as long as broad, as long 

 as carpo- and propodite together, save in the last pair of legs, in which, as is usual, the 

 propodite is very short and subcircular; the dactyli present nothing remarkable. 



I he "Siboga" collected this specimen not far from the original locality (Guijulugan, 

 Negros, Philippines). 



I) Miss Rathbun on the conlr.iry denies the existence of .1 granulate row. 



94 



