1S96.] A. Alcock — CarclnoJogical Fauna of India. 187 



i. Dorsum of carapace deeply 

 and very elegantly trilob- 



ed longitudinally E. diadumena. 



ii. Carapace hexagonal, dor- 

 sum with 4 granular swell- 

 ings arranged in a " cross "... E. wood-ma soni. 



I have not included the species referred to by Dr. Henderson as 

 Ebalia pfefferi and Ebalia fallax in this key, because the first appears 

 to belong to Dana's genus Nucia, which in my opinion has no close 

 affinity with Leach's genus, while the second is quite clearly a form 

 belonging to the Ilia alliance, as it has the Ilia fingers hands and 

 external maxillipeds. 



29. Ebalia diadumena, n. sp. Plate VII. fig. 4. 



Carapace rhomboidal, a little broader than long, its dorsal surface 

 divided into three tnmid crisply granular and most elegantly shaped 

 lobes (a gastro-carcliaco-intestinal and two branchial — forming a sort 

 of fleur de lys) by two extremely deep smooth longitudinal furrows. 

 On the middle lobe the gastric and cardiac regions are separated by 

 a shallow groove, and the cardiac and intestinal by a deep furrow. 

 The hepatic regions are also distinctly circumscribed, but are altogether 

 on a much lower plane than the rest of the carapace, and like the front 

 are only indistinctly granular. 



The front is divided, from its hardly emarginate edge down to the 

 gastric region, by a narrow deepish longitudinal groove. Behind the 

 front the angular pterygostomian ridge is somewhat prominent. The 

 lateral margins are finely crenulate : the posterior margin is almost 

 straight, with the ends somewhat dentiform. 



The surfaces of both branches of the external maxillipeds are 

 tumid and granular. 



The chelipeds in the female (male unknown) are not very much 

 longer than the carapace : the arm is trigonal and the greater part of 

 all its surfaces is crisply granular, as also are large parts of the sur- 

 faces of the wrists and hands : the fingers are not much shorter than 

 the hand and are elegantly striate-granular : the hand is not very much 

 longer than broad. 



The carapace of the adult female is 4 millim. long and 4*5 rnillim. 

 broad. 



A single ovigenous female from Palk Straits. 



Colours in spirit lilac brown, the farrows on the carapace dark 

 violet brown. 



