54 



CARIDEA, Dana. 



Caridea, Daua, U. S. Expl. Exp., Crust., pt. I. p. 528 : Stebbing, Hist. Crust., p. 224. 

 Eucyphotes, Boas, Vid. Selsk. Skr., 6 Raekke, nat. math. Aid. I. 2. 1880, p. 156. 

 Phyllobranchiata Hormalia, Spence Bate, Cliallenger Crust. Macrura, p. 480. 

 Eucyphidea, Ortmann, in Bronn's Thier Reich, Arthropoda, p. 1122. 



The pleura of the 1st abdominal somite are overlapped by those of the 2nd. 



The mandible is often, but by no means always, deeply cleft into incisor 

 and molar branches : the endopodite (palp) when present is only exceptionally 

 expanded and foliaceous. 



The coxopodite of the 2nd maxilla? is usually small and receding (occasion- 

 ally obsolete), and is never cleft into two lobes. 



The endopodite of the 1st maxillipeds is short. 



In the 2nd maxillipeds the last joint rarely articulates end-on with the 

 distal end of the propodite, though it does so sometimes : it usually lies along 

 the inner edge of the propodite, as if it were a complemental piece of the latter 

 joint. 



The external maxillipeds are 4- or 5-jointed, the dactylus and propodite 

 being fused together to form the terminal joint, and the ischium and merus, or 

 the basis ischium and merus, being fused to form the 8rd or the 2nd joint. 



The first two pairs of legs may be chelate or subchelate, but the 3rd pair 

 are always monodactylous. 



An internal appendix, usually armed with hooklets, is almost always present 

 on the base of the endopodite of the abdominal appendages from the 2nd to 

 the 5th. 



The brauchias are phyllobranchia3. 



The ova when laid are attached to the abdominal appendages of the female. 



The Caridea of the Indian Benthos and Necton fall into nine families, but 

 before indicating the inter-relations of these families I wish, for the convenience 

 of students, to insert the following artificial key for their discrimination. 



Key to the families of Indian Deep-Sea Caridea. 



I. No exopodites to the thoracic legs (except in certain species of 

 Crangonidse where the 1st pair has a small exopodite) : — / 



1. Carpus of second pair of thoracic legs unsegrnented, simple : — 



i. Second pair of thoracic legs chelate and very pre- 

 eminently robust ... ... ... Pal^monidj:. 



ii. Second pair of legs slender : — 



a. First pair of thoracic legs subchehite ... Crangonidse. 

 6. First pair of legs with forticulate chela? ... PsALiDOrODiD.E. 



