80 



posterior border is raised and gently convex. The inflated branchial regions are 

 fairly well delimited from the gastro-cardiac regions. 



Two remarkable almost straight sutures cross the carapace from side to side : 

 the anterior at the level of the junction of the antero-lateral with the postero- 

 lateral borders, the posterior at the middle of the cardiac region. These sutures 

 are remarkably distinct, equally from the exterior and from the interior of the 

 carapace. 



The side walls of the carapace, though low, meet the dorsal surface almost 

 at a right angle. The pterygostomiau regions are deeply grooved or creased 

 transversely in the neighbourhood of the large afferent branchial orifices. The 

 sternum in both sexes is widely pentagonal. 



The orbits are remarkably incomplete, their inferior border being formed only 

 by a large acute lamelliform spine and by the basal joint of the antennule and 

 of the antenna. 



The eye-stalks are long (their length being contained 6 or 7 times in the 

 greatest breadth of the carapace), slender, tapering, and slightly bent : the eyes 

 are small and hemispherical. 



The antennules have the basal joint hugely inflated, globular, quite free and 

 exposed from its origin, and freely mobile : the second and third joints, which 

 are long and slender, fold transversely on the base of the first. 



The antennge arise just below the infra-orbital spine, and outside and in the 

 same line with, the antennules : their flagellum is half the length of the carapace. 



The buccal cavity is considerably wider in front than behind : the external 

 maxillipeds are so small and slender as to leave completely exposed the mandibles, 

 the wide endostome, and a part of the wide and produced efferent branchial 

 channels. 



The epistome is linear. The fourth joint of the external maxillipeds arises 

 from the apex of the small oval third joint. 



All the trunk-legs are thickly fringed with a shaggy reddish hair. 



The chelipeds are subequal in the female, but are unsymmetrical in the 

 male : their length, half of which is formed by the hand, slightly exceeds the 

 breadth of the carapace : both hands in the female, and the smaller hand in the 

 male, are elongate compressed and sharp-edged, and have the fingers curved 

 compressed acute, slightly excavated on the inside, and indistinctly dentate 

 along the opposed edges : the larger hand of the male has the j^alm inflated. 



Of the legs, the 2nd pair is the longest, measuring rather more than twice 

 the greatest breadth of the carapace : all are slender compressed and quite smooth, 

 and all end in long sharp sabre-shaped dactyli. 



