5. Pakatelphusa (Paratelphusa) grayi, Alcock. (Fig. 17.) 



This species is very close to P. sinensis, from which it differs only in the 

 following particulars : — 



The cervical groove is distinct, even deepish in places, though not quite 

 continuous ; hence the regions are more distinct. 



The front shows no trace of division into two lobes. The teeth of the 

 antero-lateral borders are not so sharp. 



The abdomen of the male is even more decidedly hom'-glass shaped, owing 

 to the fact that the 5th segment is a long joint — its length being about equal 

 to its proximal breadth — and is contracted distally. 



The merus of the external maxillipeds is longer, though its breadth 

 slightly exceeds its length. 



In the largest specimen — an adult female — the carapace is 1 inch long, 1^ 

 inch broad, and i inch deep. 



7081-88 

 9 ■ 

 5500 



To"" 



Subgenus II. — Barytelphusa, Alcock. 

 Type : Barytelphusa jacqiiemontii (Rathb.) = " Telphusa indwa" Guerin. 



No spine on the upper border of the merus of the chelipeds ; the antero- 

 lateral borders of the carapace may be crenulate or not, but never bear a series 

 of large teeth or spines. 



The epigastric crests are either united with the post-orbital crests to 

 form one unbroken ridge on either side of the post-frontal mesogastric groove, 

 or, if the epigastric crests are separated from the post-orbital crests, the break 

 between them is vague and sometimes very indistinct, and both crests form 

 one common curve. 



The exopodite of the external maxillipeds carries a long, strong, plumose 

 flagellum. 



The cervical groove is usually very broadly and deeply impressed in all 

 its course, and usually runs to, or towards, the lateral epibranchial spine. 



The species are generally large, and dark brown in colour. 



The species of this big subgenus may be divided into two series, Avhich, 

 however, are not sharply separated, as follows : — 



I. Epigastric and post-orbital crests continuous, forming one prominent 

 transverse ridge on either side of the post-frontal mesogastric 

 groove ...... Group I. P. Jaajuemontii group. 



II. The epigastric crests are indistinctly separated from the post-orbital 



crests, but form a common curve with them . Group II. P. Iiigiibris group. 



