96 



6986 



3 ■ 



4057 



4 ■ 

 4058 



4 ■ 

 4110 

 4 ■ 

 6565-73 



9 

 6574-76 

 9 ■ 

 5559 

 ~10~' 



Khiisi Hills. 



Naga Hills. 



Base of Gavo Hills. 

 Garo Hills. 

 Barak River, Silchar. 

 Central Sylhet. 

 Garo Hills. 



H. H. Godwin-Austen. 1 ^ . 



S. E. Peal. 2 ? , 3 younff ^ . 



N. Belletty. 

 N. Belletty. 

 J. Wood-Mason. 

 .1. Wood-Mason. 

 H. Williamson. 



1 ? , 2 young S ■ 



( 16 c?, 12 $ (includ- 

 ( ing tyjies). 



1 c? , 6 y , 3 young. 

 3 young. 



1 <^- 



23. Paratelphusa (Barytelphusa) masoniana, Henderson. (Fig. 59.) 



Teiphnsa masoniana, Henderson, Trans. Linn. Soc. Zool. (2), V., 1893, p. 381, pi. xxxvii., figs. 1-4. 

 Potamon {Potamun) masonianus, M. J. Rathbun, Nouv. Archiv. du Museum (4), VI., 1904, p. 299 («5i lit.), 

 pi. xi. , fig. 10. 



I believe this " species " to be a variety of P. higubru, P. harpax being 

 the connecting form between the two. 



It agrees with P. Juguhris in all particulars but the following : — 



The carapace as a whole, and quite apart from the individual convexity 

 of the several regions, is distinctly tumid ; its relative length is a little 

 greater. 



The cervical groove runs rather to the inside than to the outside of the 

 lateral epi branchial tooth on either side. 



The front is slightly less declivous. The epigastric crests are less oblique. 



The outer orbital tooth is prominent and acute. The lateral epibranchial 

 tooth also is large, prominent, and acuminate. 



The antero-lateral borders of the carapace are not so strongly convex. 



As in harpax &ii(i. falcidigitis, the 6th segment of the abdomen of the adult 

 male is a little longer, its length very slightly exceeding its distal breadth, and 

 its sides are more concave. 



In the chelipeds the spine at the inner angle of the carpus is sharper. 



The larger cheliped exhibits the same modifications according to age and 

 sex as in P. lugubris and P. harpax. 



In the largest male the carapace is 2J inches long, 2| inches broad, and 

 U inch deep, and the greatly enlarged hand is 3fV inches long, the length of 

 the great curved dactylus being 21 inches. 



From P, harpax this form differs only in the greater convexity of the 

 carapace, the slightly sharper and more prominent external orbital and lateral 

 epibranchial teeth, and the less oblique set of the epigastric crests. But it is 

 more than probable that all these forms are nothing more than varieties of 

 P. lugahris. 



