258 Carcinological Fauna of India. 



Parthenopinea, Miers, Journ. Linn. Soc., Zool., Vol. XIV. p. 641 ; and ' Challen- 

 ger ' Brachyura, p. 91. 



The eyes are usually retractile within small circular well-defined 

 orbits, the floor of which is nearly continued to the front, leaving a 

 hiatus which is usually filled by the second joint of the antennary ped- 

 uncle. The basal antennal joint is small, and is deeply imbedded 

 between the inner angle of the orbit and the antennulary fossaa. 



The antennules fold a little obliquely. 



The Parthenojpidse are divided by Miers into two sub-families, 

 namely : — 



Sub-family I. Parthenopinse ; in whicb the carapace is sometimes 

 sub-pentagonal or ovate-pentagonal, more commonly equilaterally-tri- 

 angular, and sometimes almost semi-circular or semi-elliptical in out- 

 line ; in which the cardiac and gastric regions are usually so deeply 

 marked off from the branchial regions on either side as to make the 

 dorsal surface of the carapace trilobed; in which the chelipeds are 

 vastly longer and more massive than the ambulatory legs ; and in which 

 the rostrum is either simple or obscurely trilobed. 



Sub-family II. Eumedoninse ; in which the carapace is, commonly, 

 sharply pentagonal, with the junction of the antero- lateral and postero- 

 lateral borders strongly produced; in which the cardiac and gastric 

 regions are not conspicuously marked off from the branchial regions ; 

 and in which the chelipeds are of moderate size. 



Sub-family I. PARTHENOPINSE, Miers. 

 Miers, Journ. Linn. Soc, Zool., Vol. XIV. 1879, p. 668. 



Key to the Indian genera. 



I. Carapace not laterally expanded : — 



1. Basal antennal joint very short, not nearly 



reaching the inner canthus of the orbit : 



fingers of chelipeds very strongly incurved... LAMBRUS. 



2. Basal antennal joint nearly reaching the inner 



canthus of the orbit : fingers slightly incur- 

 ved Parthenope. 



II. Carapace more or less expanded to form a vault in which 



the ambulatory legs are concealed : — 



1. Carapace transversely triangular; greatly 



expanded both laterally and posteriorly Cryptopodia. 



2. Carapace transversely triangular; expanded 



laterally, but not posteriorly : a ridge on the 



pterygostomian region Heterocrypta. 



lOi 



