364 A. Alcock — Car etiological Fauna of India. [No. 3, 



than the ischium and carries the flagellum at the antero-external angle : 

 the exognath is extremely slender and inconspicuous. 



Chelipeds equal, stouter than the legs : fingers usually slender and 

 a little deflexed, usually without conspicuous teeth. 



Legs not much differing in length, which is moderate: their meri 

 (as also those of the chelipeds) have on the upper surface a curious 

 membranous area or " tympanum." Similar " tympana " may also be 

 present on some of the segments of the sternum. 



The abdomen in the male consists of 7 separate segments, and 

 though narrow is nowhere linear or compressed : the distal end of the 

 fourth segment is thickly fringed with bristles, and overlaps and partly 

 conceals the fifth tergum. In the female, according to De Haan, the 

 abdomen consists of 5 separate segments. 



Distribution : Tropical shores and mud-flats, from East Africa and 

 the Red Sea eastwards to Japan. Found in the same situations as 

 Gelasimus and Ocypoda. 



Key to the Indian species of Dotilla. 



I. Carapace broader than long : chelipeds not much 

 longer than the carapace, and not much differing 

 from the legs in point of length: no "tympana" 

 on the sternum : — 



1. Meropodites of legs not dilated : fingers of 

 chelae slender, without any conspicuous teeth : — 



i. Whole surface of merus of external 

 maxillipeds gyrous-sulcate: fingers not 



longer than palm D. affinis. 



ii. Only the outer-half of the merus of the 

 external maxillipeds is gyrous-sulcate : — 



a. Fingers slightly longer than the 



palm , I). Blanfordi. 



b. Fingers more than twice as long as 



the palm D. intermedia. 



2. Meropodites of the legs dilated : — 



i. Fingers of chelae without any conspicuous 

 tooth : dactyli of the legs, even of the 



last pair, shorter than the propodites D. brevitarais. 



ii. A large tooth on each finger of the chelae, 

 arranged so that when the tips of the 

 fingers are closed these large teeth meet, 

 and an hour-glass- shaped space is left 

 between the closed fingers : dactyli of the 



legs longer than the propodites D. clepsydrodactylns. 



II. Carapace at least as long as broad : chelipeds 3 or 4 

 times as long as the carapace, and much longer than 

 the legs : " tympana " present on the sternum D. myctiroides. 



