I9I5-] 



Fauna of the Chilka Lake : Crustacea Decapoda. 



259 



length of the dactylus ; the margin opposed to the dactylus is entire, but externally 

 near the base it bears a large blunt spine or tubercle. Externally the propodus is 

 longitudinally grooved near the upper border, while near the lower border is a row 

 of setae. The inner surface is smooth, but near the upper border is traversed longi- 

 tudinally by a row of pits from which setae arise. The dactylus is ridged dorsally 

 throughout its length ; there are no teeth or serrations on the lower edge. In the 

 chela of a very large male, represented merely by a cast skin (text-tig. 23), there are a 

 few scattered tubercles on the outer surface of the palm near its inferior edge ; the 

 dactylus bears two strong ridges on its upper surface and a blunt tooth in the distal 

 half of its lower margin. 



There are no spines on the basal segments of the last four legs. In the second 

 pair (text-fig. 24a) the merus bears two or three spines, one, which is subterminal, on 



Fig. 24. -Upogebia (Upo°ebia) heterocheir, sp. nov. 



a. Second peraeopod of male. 



b. Third peraeopod of male. 



c. Fourth peraeopod of male. 



d. Fifth peraeopod of male. 



e. Terminal joint of same, further enlarged. 

 /. Second pleopod of male. 



its upper edge and one or two below, one proximal and one near the middle, the latter 

 sometimes absent. The carpus bears three spines; two placed close together in the 

 distal half of its upper border and one situated beneath them, on the lower border. 

 In the third legs (text-fig. 24Ô) there are from 3 to 6 spines on the lower margin of the 

 merus and one in the same position on the carpus. In the fifth the propodus pro- 

 jects a little beyond the articulation of the dactylus; but the limb could scarcely be 

 termed subchelate (text-figs. 24^, e). 



The branchial formula consists of ten arthrobranchs on each side, arranged in 

 pairs at the base of the third maxillipedes and first four legs. There are no branchiae 

 above the fifth legs. 



Except for fine scattered setae, most conspicuous on the lateral margins, the 

 abdominal somites are smooth and polished. The sixth somite (pi. xiii, fig. 7) is the 

 longest, almost one and a half times the length of the second. In dorsal view the 



