I9I5-] 



Fauna of the Chilka Lake : Crustacea Decapoda. 



211 



upper and inner surfaces of the carpus and palm. The palm is scarcely one quarter 

 longer than broad and is not longer than the fingers ; near its proximal end on the 

 inner surface there is, in the adult male, a large coarse tubercle. The dactylus of the 

 last pair of walking legs is considerably longer than the propodus. 



The margin of the thoracic sternum is festooned with small granules, which 

 also invest the basal parts of the abdomen in both sexes. The abdomen of the male 

 (text-fig. ib) consists of two pieces only, the penultimate portion bearing a large blunt 

 tubercle at its distal end. The fused segments of the female abdomen are coarsely 

 punctured and in the middle line near the distal end there is a small granular patch ; 

 the ultimate segment is about as broad as long (text-fig. ic). 



Iyiving specimens were, as a rule, rather thickly coated with fine mud. When 

 this was removed they were found to be dull grey in colour, flecked with darker grey, 

 the walking legs and the tubercular elevations of the carapace being reddish-brown. 



Fig. i. — Ebalia malefactrix, sp. nov. 



a. Carapace of young female with unusually strong tuberculation. 



b. Carapace of male in ventral view. 



c. Carapace of female in ventral view. 



The largest specimen in the collection is a male, 10*4 mm. in length. The ma- 

 jority of adult examples are from 7 to g mm. in length ; but one female, only 43 mm. 

 long, is fully adult and bears eggs. The smallest individual, about 2 mm. in length, 

 differs in no respect from adults except that the ridges on the carapace are rather 

 more strongly pronounced and the marginal angulations a little sharper. 



Ebalia malefactrix appears to be closely related to E. sagittifera L , Alcock, and E. 

 hypsilon (Ortmann) 2 . E. sagittifera, from Karachi, the types of which I have ex- 

 amined, is a much smaller form and differs in many respects from the Chilka I^ake 



1 E. sagittifera, Alcock, Jourtt. Asiat. Soc. Bengal, LXV, p. 188 (1896) and III. Zool. 'Investigator'.. 

 Crust., pi. xxix, fig. 9. 



% Nursia ypsilon, Ortmann, in Semon's Zool. Forschungsreisen Austral, u. Malay Arch., Crust. 

 V, p. 36, pi. ii, fig. 7. 



