eathbun: crabs from the maldive islands. 125 



The chelipeds are massive, uneciual ; the larger one is about twice as long as 

 the carapace. The upper margin of the merus has a few denticles and a blunt 

 subterminal tooth ; the posterior margin and inferior surface are crossed by a 

 subtermiiial groove. The inner angle of the carpus forms a blunt, almost 

 rectangular toutli. The palm is nearly as wide as the length of its upper mar- 

 gin ; the dactylus is shorter than that margin in the larger cheliped, and longer 

 in the smaller one. The lower margin of the propodus has a shallow sinus 

 between palm and finger. The fingers are broad, white, not gaping, occludent 

 margins irregularly dentate, tips crossing, outer and inner surface each with 

 two lines of larger punctse. 



The surface of the chelipeds is similar to that of the carapace except that the 

 line wrinkles are interrupted by minute transverse irregular smooth patches. 



The merus joints of the ambulatory legs are devoid of a spine on t^e upper 

 margin. The propodus and dactylus of the last pair are considerably shorter 

 and broader than in the three preceding ; the propodus is wider than half of its 

 length measured on the anterior margin ; the dactylus is straight, not curved, 

 on its anterior margin. 



The first segment of the abdomen of the male is hidden under the carapace ; 

 the second is narrowed at the sides and does not fully cover the sternum ; the 

 third reaches the coxiB of the fifth pair of legs ; the remaining segments are 

 very narrow, the terminal one much longer than broad. 



Dimensions. — Length of carapace, 5.1 nmi. ; width at exorbital angles, 

 7.5 mm. ; greatest width, 7.8 mm. ; posterior width, 5.5 mm,; width of front 

 between the antennal notches, 2.5 mm. ; width of front between the supra- 

 orbital margins, 3.4 ram. 



Type locality. — Gan Island, Addu Atoll, at anchorage, 20 fathoms, January 

 6 ; one male. 



This species difl'ers from G. rhomboides (Linnaeus) of Europe, in its wider 

 front and shorter eyes, in the carapace being widest at the line of the lateral 

 teeth, in the absence of a spine from the legs, in the much narrower abdomen 

 of the male. 



GRAPSID^. 

 Metasesarma rousseauxi Milne Edwards. 



Metasesnrma rousseauxii Alcock, Journ. Asiatic Soc. Bengal, LXIX. 427, 1900, 



and synonymy. 

 Metasesarma rousseauxi Borradaile, Fauna Maldive Arch., I. part I. pp. 68 and 



97, 1901. 



Marco, Fadiffolu Atoll, at anchorage ; one male, one female with ova. In 

 the male, 9.2 mm. long by 10.2 mm. wide, the fingers when apposed, gape 

 except at the tips. 



