120 Records of the Indian Museum. [Vol XXIV 



C. Dactylus of last three legs simple or biunguicu- 

 late,' but without basal protuberance. 

 D. All three maxillipeds with exopods. 



E. Inner lacinia of maxillula narrow ; free-liv- 

 ing or epizootic on coelenterates or echino- 

 derms. 

 F. Carpus of first leg not segmented. 



G. Carapace not areolated ,• basal antennu- 

 lar segment normal in form ; abdominal 

 pleura usually rounded inferiorly. 2 

 H. Rostrum laterally compressed, with 

 conspicuous teeth. 



J. Carapace not depressed [free-liv- 

 ing or associated with coelenterates 

 or echinoderms] ... ... Periclimenes, p. 



J'. Carapace depressed, often very 134. 



strongly [associated with' corals] ... Harpilius, p. 2;6. 

 H' , Rostrum depressed and toothless 



[associated with crinoids] ... Pontoniopsis, p. 



G'. Carapace areolated ; basal antennular 239. 

 segment greatly attenuated anteriorly ; 

 third to fifth abdominal pleura sharply 

 pointed iiiferinrly (rostrum laterally com- 

 pressed, with dorsal teeth ; associated with 

 alcyonaria] ... ... ... Dasycaris, p. 240, 



F. Carpus of first leg segmented [rostrum 

 laterally compressed, with teeth ; cara- 

 pace not areolated ; ? free-living] ... Thaumastocaris, p. 

 E'. Inner lacinia of maxillula very broad ; 244. 

 endozootic in lamellibranchs or ascidians. 

 F. Rostrum laterally compressed in distal 

 half, toothless or with small teeth at apex 

 only ; dorsal spines of telson very small 

 [living in lamellibranchs] ... ... Anchistus, p. 247. 



F'. Rostrum depressed, toothless ; dorsal 

 spines of telson usually large [living in 

 lamellibranchs or ascidians] ... ... Pontonia, p. 259. 



D'. Exopods absent from some or all maxillipeds. 

 E. Rostrum toothless ; carapace not sculptured, 

 without supra-orbital crest; no tooth on first 

 abdominal somite; free-living (?), or asro 

 dated with gorgonians ... ... Poutonides, p. 266. 



E'. Rostrum with leelh ; carapace deeply sculp- 

 tured, with supra-orbital crest on either 

 side armed with teeth ; a mid-dorsal tooth on 

 first abdominal somite ; associated with red 

 coral ... ... ... ... Balssia, p. 267. 



C . Dactylus of last three legs simple or biunguicu- 

 late b and with a large basal protuberance. 

 D. Rostrum very long ; carapace areolated, with 

 huge antennal and supraorbital spines and with 

 pterygostomian spine ; abdominal pleura sharp- 

 ly poinled inferiorly [? free-living] ... Coutierea, p. 267. 

 D' . Rostrum little if at all longer than scale ; 

 carapace not areolated, vvilhou'' supraorbital or 

 pterygostomian spines ; antennal spine when 

 present short ; abdominal pleura interiorly 

 rounded 



' Biunguiculate in Peyiclimenes 5. str., in Tlizumastocaris and in some spe- 

 cies of Anchistm and Pontonia. 



2 The only exceptions are found in the genus Harpilius 



3 Biunguiculate only in Conch odytes. 



