Memoirs of the Indian Museum. [Vol,. IV, 



A. Lateral margin of fifth thoracic somite, seen in dorsal view, composed 

 of a single process, spinous or subacute. 



I. Cornea of eyes very small, its breadth less than greatest breadth 

 of stalk. 



A. First five abdominal somites with faint but distinct sub- 

 median carinae. 



/. Mandibular palp present ; telson with numerous granular 

 ridges or scattered tubercles on either side of median 

 crest. 



A. Lateral process of fifth thoracic somite directed 



outwards, those of two succeeding somites an- 

 teriorly rounded; inferior surface of telson smooth 

 on either side of post- anal carina ., .. latreillei, p. 24. 



B. Lateral process of fifth thoracic somite bent ob- 



liquely forwards, those of two succeeding somites 

 acutely pointed anteriorly ; inferior surface of telson 

 usually with tubercles or granular ridges on either 

 side of post-anal carina . . . . . . decorata, p. 27. 



II. Mandibular palp absent; telson without dorsal tuber- 

 cles: in adult male with a pair of huge smooth curved 

 ridges terminating on intermediate marginal teeth .. gibba, p. 28. 

 B. First five abdominal somites without trace of submedian 

 carinae. 



I. Antero-lateral angles of carapace sharply spinous. 



A. Breadth of cornea about one- third of total length of 



eye; lateral process of fifth thoracic somite short micr Ophthal ma, p. 31. 



B. Breadth of cornea about one-half of total length of 



eye; lateral process of fifth thoracic somite long . . chlorida, p. 33. 



II. Antero-lateral angles of carapace rounded . . rotundicauda, p. 33. 

 II. Cornea of eyes small or large, its breadth always greater than 



greatest breadth of stalk. 



A. Numerous sharp longitudinal carinae on either side of median 



crest of telson. 



/. Antero-lateral angles of carapace spinous ; raptorial 

 dactylus with six teeth ' ; no submedian carinae on 

 first five abdominal somites . . . . . . fasciata, p. 34. 



II. Antero-lateral angles of carapace not spinous; raptorial 

 dactylus with four teeth'; submedian carinae on all 

 abdominal somites .. .. .. miles, p. 36. 



B. No longitudinal carinae on either side of median crest of telson. 



I. Raptorial dactylus with more than four teeth 1 ; telson 

 with short (normal) marginal teeth. 

 A. Median carina of carapace, when present, not bifur- 

 cated anteriorly. 



1. Median carina of carapace absent; mandibular 

 palp present; raptorial dactylus with six 

 teeth ' ; lateral processes of sixth and seventh 

 thoracic somites posteriorly rounded. 

 a. Submedian carinae absent from at least first 



Including the terminal tooth 



