rgiS-] Stani^ey Kemp : Crustacea Decapoda. 301 



males. The spine at the inner angle of the carpus is strong and 

 sharp (fig. 18) and is much better developed than in the Abor ex- 

 amples of P. adiatretum. The fingers of the chela are grooved. 

 In adult males the chelipedes are very unequal and, as in P. adia- 

 tretum, the fingers of the larger claw when closed leave between 

 them a huge gap, meeting only at the tips (fig. 17). The teeth on 

 the fingers appear to be very variable in number and position and 

 the tufts of hairs found in P. adiatretum var. lophocarpus are en- 

 tirely absent. 



The mandibular palp is simple. The merus of the outer 

 maxillipedes is much broader than long and its anterior margin is 

 rather deeply concave ; the exopod is provided with a long flagel- 

 lum. 



This species appears to reach a much greater size than that 

 described by Alcock, but the characteristic differences between the 

 two forms are quite distinct even in the very smallest individuals. 

 In a large male the carapace is 38 mm. broad, 27 mm. long and 

 16 mm. deep. 



It will be noticed that in the possession of a rudimentary 

 epibranchial tooth and prominent post-orbital ridges P. supercili- 

 osum departs somewhat from the definition of the sub-genus Geotel- 

 phusa as laid down by Alcock. The affinities of the species with 

 P. adiatretum are, however, clear. 



The twelve specimens obtained were found in hill streams 

 between altitudes of 600 and 2000 ft. 



Jan. I3th-i7th, 1912. Six males, some with symbiotic Tem- 

 nocephalidae, in the Yembung river (Regd. no. -'^*). 



Jan. 19th, 1912. One male in the Egar stream between Reng- 

 ing and Rotung C^J). 



Feb. 9th, 1912. Three males and one female, some with 

 symbiotic Temnocephalidae, in the Yembung river (— '). 



March 26th, 1912. Four males, two very large, in a stream 

 near Balek (■^', types). 



Sub-genus Acanthotclphusa, Ortmann. 

 Potamon (Acanthotclphusa) fcae, (de Man). 



1898. Paratelphusa feae, de Man, Ann. Mus. Civ. Genova (2), 



XIX, p 393, Pl- iv, fig. 3. 

 T910. Potamon (Acanthotelphusa) feae, Alcock, Cat. Indian 



Decapod Crust., pt. I, fasc. ii, p. 66, pi. xi, fig 51. 



The Abor specimens are all small, the carapace of the largest 

 being only 17 mm. in breadth. 



The carapace is much less distinctly areolated than in the four 

 larger specimens examined by Alcock ; the post-orbital crest 

 does not form the definite tubercles found in those individual?, 

 but exists as a very obscure and ill-defined eminence which 



