J900.] A. Alcock — Carcinological Fauna of India. 375 



thickset. The length of the longest (second) pair of legs is 2^ times 

 that of the carapace, that of the last pair of legs is very little more than 

 that of the carapace. 



Two young males from Karachi : the carapace 65 millim. long and 

 11 millim. broad. 



Macrophthalmus, Latreille. 



Macrophthahmis, Latreille, in Cuvier Regne An. (ed. 2) Vol. IV. p. 44 (1829) : 

 De Haan, Faun. Japon. Crust, p. 26: Milne Edwards, Hist. Nat. Crust. II. 63, and 

 Ann. Sci. Nat., Zool. (3) XVIII. 1852, p. 155: Dana, U. S. Expl. Exp., Crnst. pt. I. 

 p. 312: Miers, Challenger Brachyura, p. 248. 



Cam pace depressed, quadrilateral, broader than (sometimes more 

 than twice as broad as) long : the regions are well defined, the cervical 

 and branchial grooves being characteristically conspicuous both on the 

 dorsum 6'f the carapace, and on the lateral border where they cut out 

 two prominent teeth or lobes. 



Front deflexed, narrow, often a narrow lobe as in Gelasimus : its 

 free edge never approaches the epistome. The orbits are narrow 

 trenches occupying the whole anterior border of the carapace between 

 the front and the anterolateral angles : eyestalks usually very lone and 

 slender, as in Gelasimus. The autennular flagella, which are rather 

 small, fold transversely beneath, but are not concealed by, the front. 

 The antenna? stand at the inner angle .of the orbit : the basal joint is 

 short, and the flagellum is of good length. 



Epistome very short fore and aft, almost linear, but well delimited 

 from the palate. Buccal cavern somewhat arched anteriorly. The 

 external maxillipeds have a broad foliaceous ischium and merus (the 

 latter about half the length of the former) and a coarse flagellum 

 articulating with the antero-external angle of the merus : though the 

 ischium and merus may not quite meet across the middle of the buccal 

 cavern, the narrow interval that may exist between them is largely 

 filled by the flagella, so that the underlying parts are concealed. 



The chelipeds differ greatly in the sexes : in the female they are 

 equal, and are shorter and slenderer than any of the legs except, 

 perhaps, the short and weak last pair : in the adult male they are equal 

 or subequal, and are longer and stouter than any of the legs except 

 perhaps, the particularly large and stout penultimate pair : in both 

 sexes the fingers are curiously deflexed and bent or curved inwards 

 distally. 



Of the legs, the first and last pairs are usually singularly short and 

 slender compared with the second and third pairs : the third pair are 

 the longest and stoutest, being nearly or quite as large as the chelipeds 

 J. n. 49 



