I9I3'] STANI.EY Kemp : Crustacea Decaf oda. 295 



orbital crest near the lateral border is faint and the dorsal surface 

 in these regions is, except for the rugosities, smoothly curved from 

 the orbit backwards. In P. ahorense, however, the surface in the 

 neighbourhood of the outer orbital angle is situated at a much 

 lower level than the lateral portions behind the post-orbital crest, 

 the latter being in this part precipitous and becoming steeper and 

 more strongly emphasized the nearer it approaches the epibran- 

 chial lobe. It is in the mutual relations of the surface of the cara- 

 pace in the neighbourhood of the epibranchial lobe and the orbit 

 that the readiest distinctions between the two species are to be 

 found {cf. figs. 4 and 8). 



Behind the epibranchial lobe the antero-lateral margin is de- 

 fined by a crenulate ridge which is relatively much shorter and 

 curves inwards further and more abruptly than in P. sikkiniense. 



The front is deflexed, a trifle more than a third the breadth 

 of the carapace, and the area between its margin and the epigas- 

 tric crests is tuberculo-rugose. 



Posteriorly the whole carapace is more definitely narrowed 

 than in the allied species, or rather, appears to be so, because the 

 lateral parts of the dorsal surface slope downwards somewhat sharply , 

 leaving only a trifle more than one-third of the actual breadth 

 on the same level as the median horizontal line. The distinction 

 in this respect between the present species and P. obliteratum is 

 very marked. 



The antepenultimate abdominal segment of the male is shorter 

 than the penultimate (fig. 5), and in this particular P. ahorense 

 resembles the Nepalese examples of P. sikkiniense recorded by 

 Alcock in his Catalogue as P. sikkiniense var. (fig. 6). In t^^pical 

 P. sikkimense the antepenultimate segment is longer than the 

 penultimate (fig. 7). 



The terminal segment of the mandibular palp is simple. The 

 merus of the external maxillipedes is a trifle broader than long, 

 and in no case is there a vestige of a flagellum on the exopod. 



The chelipedes are equal in the adult female, but markedly 

 unequal in males of similar dimensions ; they are if anything slighth^ 

 smoother than in the allied species. The spine at the inner 

 angle of the carpus is sharp and the fingers are almost as long as 

 the palm, pitted, but not fluted, and between them when the claw 

 is closed there is no appreciable gap. In adult males the palm of 

 the larger claw is strongly inflated, more so than in P. sikkhnense. 



The legs are decidedly more slender than in P. sikkiniense and 

 the propodus of the penultimate pair is more than two and a half 

 times as long as broad. 



The three specimens in the collection are of closely similar 

 size. The breadth of the carapace varies from 17 to 18 mm., the 

 length from 14 to 15 mm. and the depth from 8-5 to 9*5 mm. In 

 life two of the examples were rather conspicuously mottled with 

 deep brown on a pale brown or olivaceous ground, the colouring 

 being particularly noticeable on the side walls of the carapace. 

 The female ic ovigerous and carries a number of eggs, in life of a 



