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



pace ; lateral margin of seventh thoracic somite 



not bilobed . . . . . . boops, p. 55. 



2. Rostrum without median carina ; breadth of 

 cornea much less than one-third of median 

 length of carapace ; lateral margin of seventh 

 thoracic somite distinctly bilobed. 



a. Cornea set almost transversely on eye- 



stalk ; outer inferior margin of raptorial 

 merus terminating in a sharp tooth ; an- 

 terior lobe of seventh thoracic somite short quinquedcntata , p. 52. 



b. Cornea set obliquely on eyestalk ; outer in- 



ferior mai gin of raptorial merus not ter- 

 minating in a tooth ; anterior lobe of 

 seventh thoracic somite well-developed, 

 more than half as long as posterior lobe . . gonypetes, p. 54. 

 B. Raptorial dactylus with six teeth. 1 



1. Cornea not wider than eyestalk; rostrum with 



short median carina ; surface of carapace and 



abdomen with a coarse mesh-like reticulation foveolata, p. 58. 



2. Cornea very clearly wider than eyestalk ; ros- 



trum without median carina ; surface of cara- 

 pace and abdomen smooth or rugose, never 

 reticulate. 



a. Cornea set transversely on eyestalk. 



i. Posterior half of median carina of cara- 

 pace, anterior to cervical groove, 

 simple ; submedian carinae of fourth 

 abdominal somite ending in spines . . nepa, p. 60. 



ii. Posterior half of median carina of cara- 

 pace, anterior to cervical groove 

 finely bicarinate throughout almost 

 its entire length ; submedian carinae 

 of fourth abdominal somite not ending 

 in spines . . . . • . holoschista, p. 64. 



b. Cornea set very obliquely on eyestalk. 



i. lateral carinae of first five abdominal 

 somites simple — not bicarinate. 

 a. No rows of tubercles on either side 

 of median crest of telson. 

 (i) Anterior breadth of carapace 

 less than half its median 

 length, including rostrum; 

 anterior bifurcation of medi- 

 an carina of carapace rarely 

 altogether obsolete ; anterior 

 margin of ophthalmic somite 

 convex, truncate or emargin- 

 ate; dorsal surface of cara- 



Includiug the terminal tooth. 



