128 A. Alcock — Carcinolofiical Fauna of India. [No. 3, 



than long and flattisli. Brancbial groove usually present, cervical 

 groove sometimes present. 



Front broadly triangular, sometimes notched at tip. Antennal 

 flagella not so long as the carapace. 



External maxillipeds typically opercular, completely closing the 

 buccal cavern. 



Chelipeds equal or sligbtl}^ unequal, generally much stouter than 

 the legs. 



First three pair of legs stout, about as long as the chelipeds. 

 Fourth (last) pair of legs dorsal and rudimentary. 



The abdomen in both sexes consists of 7 segments, and there is a 

 pair of lateral platelets intercalated between the last two segments. 



Tlie gills are phyllobranchise but sometimes show the transition 

 from tricho- to phyllobranchise. The gill-plumes are 16 (?) on either 

 side. 



Epipodites are present on the chelipeds and first three pair of legs. 



Sternal grooves of the female ending at the level of the genital 

 openings. 



To this family belong (1) Dynomene and (2) Acanthodromia, both of which are 

 represented in Indian Seas. 



Family III. Dromiid^, reslr. 



Carapace variable, sometimes as long as or even a little longer 

 than broad, sometimes slightly broader tlian long ; generally strongly 

 convex in both directions, sometimes flat ; commonly ovoid or subcir- 

 cular, occasionally pentagonal. 



* Branchial groove almost always conspicuous, the true cervical 

 groove present or absent on the dorsum of the carapace. 



Front usually cut into 3 teeth, the middle one of which is always 

 on a much lower plane than the others and is often of insignificant size 

 or even absent : the front is rarely triangular, without lateral teeth. 

 Antennal flagella shorter than the carapace. 



External maxillipeds typically opercular, completely closing the 

 buccal cavern. 



Chelipeds equal, generally much stouter than the legs. 



First two pair of legs generally stout, not much shorter than the 

 chelipeds. 



Last two pair of legs generally much reduced in length and slender, 

 subdorsal and prehensile. There is a tendency for the fourth (last) 



* The braneliial groove of Bouvier, which by most authors is called tlie "cervi- 

 cal " groove. 



