176 A. Alcock — Carcinological Fauna of India. [No. 2, 



19. Tlos petrseus, A. Milne-Edwards. 



Tlos petrseus, A. Milne-Edwards, Nouv. Archiv. du Mus. X. 1874, p. 51, pi. iii. 

 fig. 1. 



Carapace broadly pentagonal ; with the front somewhat produced, 

 bluntly ti'iangular, and slightly emarginate. The margins of the cara- 

 pace are thickened, roughened, and somewhat upturned. Each wing 

 of the carapace shows a division into three broad lobes, but the divisions 

 are only sutures, not gaps. Except for a ridge running from the front 

 to the cardiac region, and except for a granular node just external to 

 the cardiac region on either side and for a little thickening between 

 each node and the postero-lateral angle, the surface of the carapace is 

 smooth and concave. The under surface of the body is granular. The 

 orbits are almost ventral in position, and the eyes are not visible in a 

 dorsal view. 



The chelipeds in the female are not quite as long as the 

 carapace: the arm is trigonal with enlarged granules along all its 

 borders, the wrist and hand are rough, and the dactylus is fluted. The 

 hand is as broad as long, and is continued without any sort of constric- 

 tion into the great shovel-shaped immobile finger, which is about as 

 long as the hand and vastly more massive than the dactylus. The legs 

 are compressed, and have their dorsal and ventral surfaces granular : 

 in flexion they are hidden beneath the wings of the carapace. 



In the abdomen of the male the terga although a good deal 

 fused are all separately recognizable, and there is a denticle in the 

 middle line on the 4th and 6th. 



An adult (ovigerous) female has the carapace 7 millim. long, and 

 10 millim. broad. 



Andamans, Off Ceylon 34 frus., Pedro Shoal 20 fms. Eight speci- 

 mens. 



20. Tlos patella, n. sp. Plate VIII. fig. 4. 



Carapace transversely oval, and closely covered with granules 

 which under the lens are fungiform : the carapace is traversed by a 

 longitudinal ridge, and the branchial regions are convex in their poste- 

 rior part ; but the wings of the carapace are cupped dorsally, much as 

 in T. petrmus, and are divided by closed sutures into three broad lobes. 



The front hardly breaks beyond the general outline of the carapace, 

 and has its edge thickened. The eyes can just be seen in a dorsal view. 



The intestinal region is convex backwards, and the bilobed (true) 

 posterior margin still more so. 



The under surface of the body is granular, much like the upper 

 surface. 



