1900.] A. Alcock — Carcinological Fauna of India. 415 



(2) the front is not so broad, its extent being only half the breadth 

 of the carapace : 



(3) the meropodites of the legs are not so broadly foliaceous, their 

 greatest breadth, in the middle two pairs, being less than half their 

 length. 



The Indian Museum possesses a single specimen from Mergui. 



99. Sesarma bidens (De Haan). 



Grapsus (Pachysoma) bidens, De Haan, Faun. Japon. Crust, p. 60, pi. xvi. fig. 4, 

 and pi. xi. fig. 4. 



Sesarma bidens, Dana, U. S. Expl. Exp. Crust, pt. I. p. 353 : Milne Edwards, 

 Ann. Sci. Nat., Zool., (3) XX. 1853, p. 185: Stimpson, Proo. Ac. Nat, Sci. Philad. 

 1858, p. 105 : Heller, Novara Crust, p. 64 : Hilgendorf, in v. d. Decken's Reisen 

 Ost-Afr., Crust., p. 91, pi. iii. fig. 3a : Hoffmann, in Pollen & Van Dam, Faun. 

 Madag. Crust, p. 24: Miers, Ann. Mag. Nat. Hist. (5) V. 1880, p. 313, and Zool. 

 H. M. S. Alert, pp. 184, 246 : Kingsley, Proc. Ac. Nat. Sci. Philad. 1880, p. 214: 

 de Man, Notes Leyden Mus. II. 1880, p. 28, and Zool. Jahrb., Syst., II. 1887, p. 658, 

 and in Weber's Zool. Ergebn. Niederl. Ost-Ind. II. p. 330 : Lenz & Richters, 

 Abb. Senck. Nat. Ges. XII. 1881, p. 425: Burger, Zool. Jahrb., Syst., VII. 

 1893-94, p. 628 : Ortmann, ibid. p. 726 : Nobili, Ann. Mus. Genova (2) XX. 1899, 

 p. 269. 



Sesarma Dussumieri, Milne Edwards, I. c. supra: TozZetti "Magenta" Crust. 

 p. 145, pi. ix. figs. 3 a-f: Kingsley, Proc. Ac. Nat. Sci. Philad. 1880, p. 215 : de Man, 

 Zool. Jahrb. Syst. II. 1887, p. 659, and IX. 1895-97, p. 208, and Journ. Linn. Soc, 

 Zool., XXII. 1888, p. 177, pi. xii. figs. 8-12: Ortmann, Zool. Jahrb., Syst., VII. 

 1893-94, p. 726. 



Sesarma lividum, A. Milne Edwards, Nouv. Archiv. du Mus., V. 1869, Bull. 

 p. 25, and IX. 1873, p. 303, pi. xvi. fig. 2 : Brocchi, Ann. Sci. Nat., Zool., (6) II. 1875, 

 Art. 2, p. 83 {male appendages) : Kingsley, torn. cit. supra, p. 216 : de Man, Archiv. 

 f. Naturges. LIII. 1887, i. p. 381, pi. xvii. fig. 1, and Zool. Jahrb. Syst. II. 1887, 

 p. 659, and Journ. Linn. Soc, Zool., XXII. 1888, p. 180. 



Sesarma Haswelli, de Man, Zool. Jahrb., Syst., II. 1887, p. 658, and Journ. Linn. 

 Soc, Zool., XXII. 1888, p. 175. 



This species very closely resembles 8. quadratum, from which it 

 differs in the following characters : — 



(1) there is a small sharp tooth on the lateral border of the 

 carapace, immediately behind the outer orbital angle : 



(2) the carapace is slightly less transverse (though decidedly broader 

 than long) : 



(3) the transverse ridges on the upper surface of the dactylus 

 of the male chelae are coarser and shorter and more tubercle-like. 



In the Indian Museum are 52 specimens from the coasts of the 

 Bay of Bengal, Andamans, Nicobars and Ceylon. 

 J. ii. 54 





