Subgenus iii. — Oziotelphusa : — 



24. P. hi/drodiomiis (Herbst). 



25. „ var. 



26. P. Immieri (Rathb.). 



27. Pnratelphusa sp. 



Subgenus iv. — Phricotelimiusa : — 



28. P. callianira (de Man). 



29. P. sp. 1 prox. callianira. 



30. P. sp. 2 prox. caUiatiira. 



31. P. elegans (de Man). 



32. P. gageii, A. A. 



33. P. campestris, A. A. 



34. P. carinifera (de Man). 



Subgenus v. — Liotelphisa : — 



35. P. km (W.-M.). 



36. ,, var. 



37. „ var. ijii/idrtild, A. A. 



38. P. austrina, A. A. 



39. Paratelphusa sp. 



Subgenus vi. — Globitelphusa : — 



40. P. bakeri, A. A. 



41. „ var. cijlindius, A. A. 



42. P. pistorica, A. A. 



43. P. gubernatoris, A. A. 



44. P. pilosipes, A. A. 



45. P. froiito, A. A. 



Genus III.— GECARCINUCUS 



Subgenus i. — Gecarcinucus : — 



1. G . jacqiiemontii, Edw. 



2. G. edwardsi, W.-M. 



Subgenus ii. — Cvlindrotelphusa : — 



3. G. steniops (W.-M.). 



Habits. — The Potamonidce, though a few species can also exist quite well 

 on the one hand in brackish water and on the other hand in damp jungle, are 

 typical inhabitants of fresh water. They are found in ponds, lakes, streams, 

 rivers, and marshes ; and though they flourish most at low or inconsiderable 

 levels in the tropics, they extend into the warmer temperate regions, and are 

 also quite common at considerable elevations in the torrid zone. 



Among the Indian Potamonidce we find examples of all these modes and 

 stations of life. For instance, in the swamps of Lower Bengal, a very common 

 species is Paratelphusa spinigera : in the rainy season it can be seen in any 

 Calcutta tank, often reposing on the bank, half-immersed in the water : in the 

 cold season it may be found in the jheels in swarms, half-buried in the mud : 

 in the hot season, when the surface-waters dry up, it digs deep burrows to get 

 down to the ground-water. The same species, P. spinigera, on the one hand 

 ascends the Ganges and Jumna as far as Hardwar and Saharanpur, and the 

 Jhelum valley to an elevation of 2000 feet, and on the other hand does not 

 object to the brackish water of the Gangetic delta. 



In the jmigles of the Western Ghauts, up to a height of 4000 feet, more 

 than one species, and in the neighbom'hood of Darjeeling, at elevations of 

 5000 to 7000 feet, at least two species of these crabs may be met with, far from 

 any collection of water, during and shortly after the rainy season. 



In ponds in the plains of Southern India, where the temperature is never 

 very low, Paratelphusa hydrodromus ( = Telphusa leschenaultii of many authors) 

 is common : in river-pools in Baluchistan, at an elevation of over 6000 feet, 

 Avhere the winter cold may be intense, varieties of Potamon fluviatile can find 

 a living. 



The eggs of Potamonidm are comparatively large, and are not extremely 



