1900.] A. Alcock — Car etiological Fauna of India. 289 



anterior border of the merus, aud their exognath is generally broad and 

 is exposed throughout. The male abdomen, though not narrow, rarely 

 covers all the space between the last pair of ambulatory legs. 



Subfamily III. Sesarminjd. (Sesarmacea and Gyclograpsacea part, 

 Milne Edwards ; Sesarminae, Dana, Kingsley, Miers, Ortraanu). Front 

 strongly deflexed : the lower border of the orbit commonly runs down- 

 wards towards the angle of the buccal cavern : the external maxillipeds 

 leave a wide rhomboidal gap between them, an oblique hairy crest 

 traverses them from a point near the antero-extemal angle of the ischium to 

 a point near the antero -internal angle of the merus, their palp articulates 

 either at the summit or near the antero-external angle of the merus, 

 and their exognath is slender and either partly or almost entirely 

 concealed. The male abdomen either fills or does not quite fill all the 

 space between the last pair of ambulatory legs. Antennal flagella 

 variable. 



Subfamily IV. Plagusiin^. (Plagusiacea, Milne Edwards ; Pla- 

 gusiinae, Dana, Kingsley, Miers, Ortmann). The front is cut into lobes 

 or teeth by the antennnlar fossae, which are visible in a dorsal view as 

 deep clefts : the lower border of the orbit curves down into line with 

 the prominent anterior border of the buccal cavern : the external 

 maxillipeds do not completely close the buccal cavern but they do not 

 leave a wide rhomboidal gap, they are not traversed by any oblique 

 hairy crest, their palp articulates near the antero-external angle of the 

 merus, and their slender exposed exognath has no flagellum. The 

 antennal flagella are short. The male abdomen fills all the space 

 between the last pair of legs. 



Family GEOCARCINID^E, Dana. 



Gecarciniens, Milne Edwards, Hist. Nat. Crust. II. 16. 



Gecarcinacea, Milne Edwards (pt.), Ann. Sci. Nat., Zool., (3) XX. 1853, p. 200. 

 Gecarcinidse, Dana (pt.), U. S. Expl. Exp. Crust, pt. I. p. 374. 

 Geocarcinidse, Miers, Challenger Brachyura, p. 216. 



Gecarcinidse, Ortmann (pt.), Zool. Jabrb. Syst. VII. 1893-94, pp. 699, 732, and in 

 Bronn's Thier Reich, torn. cit. p. 1178. 



I think it inadvisable to subdivide this small group, which Milne 

 Edwards, with more justice, regarded as itself only a subfamily of the 

 Grapsidae. 



Qecarcinucus is a Telphusoid and should not be referred here. 

 Epigrapsus and Grapsodes, if they are distinct from one another, belong 

 here rather than to the Grapsidae. 



