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cervical groove is nearly straight, and from either end parts a very short branchio-cardiac 

 furrow; these are the only sulci of the carapace, which is everywhere finely punctate and does 

 not show distinct regions; at the level of the branchio-hepatic grooves we may observe a very 

 slightly inflated portion of an oval shape. Epigastric lobes, so easily to be detected in the 

 laro-e species and also in the small Ps. aldus. are wholly absent, and the front, that is exactly 

 half as wide at the anterior margin as the maximum breadth of the carapace, passes without 

 any demarcation into the epigastric region; it islaminar and prominent, projecting 

 some way beyond the bases of the antennulae (fig. i a), slightly sinuous in the 

 middle of the fore margin and with rounded lateral angles; the side margins are concave, and 

 the transition between them and the supra-orbital margin, which latter is directed straightly 

 outward but somewhat sinuous, is marked by a very shallow and inconspicuous notch. External 

 orbital angle very slightly projecting, directed inward, with the lateral margin straight, and 

 about lYo times as long as that of the following tooth; anterior epibranchia! tooth very little 

 prominent, only marked by a sudden alteration of the direction of the lateral margins of the 

 carapace, as these are diverging backward anteriorly, but behind the anterior epibran- 

 chial teeth the margins are converging backward, so that at the level of these 

 teeth the carapace attains its maximum breadth ; a second epibranchial tooth is most inconspi- 

 cuous, and behind it the margins are even somewhat concave , the posterior margin of the 

 carapace is shorter than the width of the anterior margin of the front. Antennules and antennae 

 do not present anything remarkable; the infra-orbital margin is deeply fissured and beneath it 

 a suborbital crest runs obliquely backward, this crest proves to be microscopically striated at 

 strong magnification. Pterygostomial regions with an oblique ridge on either side; the dorsal 

 part of the region finely reticulate. Xasal plate triangular; epistome distinct, but very short. 

 External maxillipeds essentially resembling those of Ps. albus: merus with a large and distinct 

 auricle at the outer margin and a deep notch at the anterior border, e.xognath twp-thirds of 

 the width of the ischium (fig. \a). 



The abdomen of the cf is somewhat narrower than that of the other species: whereas 

 in Ps. setosus, crassiis and albns the lateral margins onl\- sligrhtlv converee towards the 

 terminal segment and the penultimate segment is abruptly narrowed anterior])-, the abdomen 

 of Ps. laiiiger presents more distinctly converging, even somewhat concave, side margins, that 

 are not convex at the anterior part of the penultimate segment. The terminal joint is oblong, 

 with the tip much rounded, longer than broad at the base and longer than the penultimate 

 segment, which itself is again longer than the antepenultimate one (fig. i d). 



The chelipeds are unequal, the left being slightly the larger. xMeropodite short and 

 thick, scarcely projecting beyond the carapace, unarmed, with rounded margins, but the inner 

 margin fringed with a row of woolly hairs, increasing in length distally. Wri.st 

 globular at upper surface, with inner angle subrectangular : immediately beneath inner 

 margin, especially anteriorly, a tuft of similar woolly h ai r s is f o u n d , and. 

 if the cheliped be folded, these hairs cover the proximal naked portion of the inner surface 

 of the palm. Chela bulky, palm longer than fingers and rather high; upper border rounded; 

 a large tuft of woolly hairs covers the distal portion of the inner surface 



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