15:2 



terga overlap one another : the abdominal pleura behind the first are well 

 developed, but the first is almost obsolete : the telson is broadly truncated. 



Two antennular flagella of moderate length, much longer than the peduncle. 

 The antennal scale is usually present, but may be absent : the antenna! peduncle 

 is five-jointed, and the flagellum lash-like. 



Mandible with the incisor portion separated from the molar by a groove, 

 the incisor portion much the larger and more prominent : mandibular palp 

 incurved, three-jointed. 



Palp of the 1st maxilla bi-articulate : coxa and basis of 1st and 2nd maxilla 

 and of 1st maxilliped almost equally well developed, the coxa of the 2nd maxilla 

 deeply cleft transversely, the exopodite of the 1st maxillipeds not stouter than 

 the endopodite. 



All the maxillipeds have well developed flagellate exopodites and large 

 epipodites, the external maxillipeds are stout, pediform, and 7-jointed, but are 

 much shorter than any of the thoracic legs. 



The thoracic legs are all 7-jointed, but in the 1st pair there is no indepen- 

 dent motion at all between the 2nd and 3rd joints (basis and ischium). The first 

 three pairs are chelate, the 1st pair being much the longest and most massive : 

 the last two pairs are monodactylous. Large foliaceous epipodites are present 

 on the first four pairs, these being completely independent of the podobranchise. 



The abdominal appendages behind the 1st pair are biramous. Those of the 

 1st pair are uniramous, weak and slender in the female, but stout and rigid in. 

 the male, in which sex they are channelled along the inner surface so as to form 

 by their apposition a tubular organ of copulation. In the male also the endopod- 

 ite of the 2nd pair of appendages bears, on its inner edge, a rigid appendix that 

 can be ensheathed within the tube formed by the apposition of the 1st pair. 



Synopsis of the genera of Nephropsidae of the Indian Benthos. 



I. A foliaceous antennal scale is present : 



1. Eyes very large and well-pigmented : third joint of the antennular 



peduncle shorter than the 2nd : 2nd pair of legs a little stouter 



than the 3rd ... ... ... ... ... NEPHROPS. 



2. Eyes obsolescent, not pigmented and not differentiated from the 



eyestalks : 3rd joint of the antennular peduncle as long as or 

 longer than the 2nd : 2nd pair of legs slenderer and much longer 

 than the 3rd ... ... ... ... ... PHOBERUS. 



II. No autennal scale : eyes obsolescent, without pigment and not properly 



differentiated from the eyestalks : 3rd joint of the anteimular peduncle 

 much longer than the second : 2nd pair of [legs decidedly stouter than 

 the 3rd ... ... ... ... ... ... NEPHROPSIS. 



