XXIX. DIAGNOSES OF NEW SPECIES 



AND VARIETIES OF FRESHWATER 



CRABS. 



By A. A1.COCK, F.R.S. 



No. 4. 



Genus Paratelphusa, Edw, 

 (Type : P. tridentata, Edw.) 

 Subgenus Paratelphusa. 



Paratelphusa {Parafelphusa) trilobata, sp. nov. 



Differs from P. spinigera only in the following particulars : — 



The carapace is flatter, and the ' ' cervical groove ' ' is broader : 

 its antero-lateral border on either side is produced between the 

 external-orbital and lateral-epibranchial spines into a broad and 

 very prominent, laminar lobe. 



The subterminal spine on the upper border of the arm is blunt 

 and coarse. 



From Sibsagar, Assam : a single adult female. 



Paratelphusa (Paratelphusa) hlanfordi, sp. nov. 



This is an aberrant member of the subgenus, having no spines 

 or lobes between the external-orbital and lateral-epibranchial tooth, 

 and no spine on the upper border of the arm. It is, however, closely 

 related to P. spinigera. 



It has much the appearance of P. spinigera except that its 

 carapace is flatter ; but is distinguished from that and every other 

 Indian species but one in the form of the fingers, which have broad, 

 blunt, ' ' spooned ' ' tips. 



It has nothing to do with Paratelphusa spinescens, Caiman, 

 which has spiny antero-lateral borders and is not a Paratelphusa 

 at all since it has the simple mandibular palp of Potamon. 



From various places in Baluchistan : 10 males, 10 females. 



Paratelphusa {Paratelphusa) grayi, sp. nov. 



This is very close indeed to P. sinensis, from which it dift'ers 

 only in the following particulars : — 



The "cervical groove" is distinct, and in places is almost 

 deep : the front shows no trace of division into two lobes : the teeth 



