63 



Buccal cavern quadrangular, very well defined anteriorly; the external 

 maxillipeds do not nearly cover it, but leave the efferent branchial channels per- 

 manently widely open ; the endostomial ridges that define these last are well 

 defined posteriorly, but do not reach the anterior border of the buccal cavern. 



Chelipeds in the female, markedly unequal, fingers long, pointed. 



Legs long, slender, compressed, spiny. 



As there is only a single female in the Indian Museum, I cannot be sure of 

 the place of this genus in the system. It probabli/ belongs to the Cancroidea, 

 and should be placed near Galene: 



Platypiltunnus gracilipes, Wood-Mason. 



Platypilumnus gracHipei. Wood-MaBon MS., Alcock, Ann. Map. Nat. Hist. May, 1894, p. 401 -. 111. Zoo!. Inves- 

 tigator, Crust, pi. xW. fig. 6 : J. A. S. B., Vol. LXVII. pt. 2, 189S, p. 233. 



Carapace much depressed, perfectly flat above, with the surface nearly 

 smooth centrally and very finely and closely granular laterally, and with the 

 regions indistinctly defined. The front has the form of a horizontally projectino- 

 bilobed lamella, with the free edge sharply and very evenly spinate and the sides 

 turned abruptly downwards. The margins of the orbit are spinulate, the upper 

 margin the more distinctly so, and the lower margin terminates internally in a 

 strong oblique spine, the point of which inclines towards the sharply vertical 

 tooth formed by the already mentioned downfolding of the lateral edge of the 

 frontal lamella. 



The antero-lateral borders of the carapace, which are arcuate and are 

 shorter than the postero-lateral, are armed with three large spines, in front of, 

 between, and behind which are several spinules. 



The pterygostomian regions are large and inflated, and the branchial aper- 

 tures, especially the efferent aperture, are large and patulous. 



The eyestalks are large and are of moderate length ; the corneal region is 

 rather small. 



The antennules are long and are transversely folded, their basal joint is 

 large and inflated. 



The antenna are long, their basal joint is slender and free ; the second joint 

 lies loosely in the internal orbital hiatus. 



The inner edge of the meropodite of the external maxillipeds is convex, 

 with a pair of little spines at the summit of the convexity ; the succeeding joint 

 arises at the antero-internal angle. 



The thoracic legs are furnished with many spines and long hairs. The 

 chelipeds, which are robust, are unequal ; their prismatic arm has all its borders 

 spiny ; the short inflated wrist is sharply granular and spinulate in the distal 



