84 Records: of I lie Intlian Miiseuvi. [YoL. XIV, 



The antpro-latoi'al liordor (toxt-fi!i\ ^a) is sharper and nuich more 

 strontily reflected u])\vards tlian in P. andersonianum. It is separated 

 from the coarsely oranular e])ibraneliial reoion by a deep smooth croove 

 and its margin, instead of being serrulate, is spiniilose. At the posterior 

 end of the border the sj)inules are small and closely packed ; anteriorly 

 they are larger and more widely spaced ; the foremost is a large epi- 

 branchial tooth which frequently beai's one or more granules on its 

 edges. 



The antennular fossae and epistome are much as in the relat(»d 

 form. The ischium of the outer maxillipedes (text-fig. \h) bears the 

 usual groove ; the merus is as long as broad and is rounded in outline, 

 rather than irregularly hexagonal as in typical specimens of P. ander- 

 sonianum. 



The chelae are more or less of a size. The merus is similar to that of 

 P. andersonianum, but the granulation is much crisper, the serrated 

 margin being spinulose and the tooth near the distal end of the inner 

 face becoming a sharp spine with accessory spinules at the base. The 

 carpus is smoother above and is not, or not appreciably, umbilicate. 

 On the upper surface of the palm there are some small and inconspicuous 

 tubercles which extend a little way down the outer face ; the lower half 

 of the outer surface is quite smooth. The fingers are more compressed 

 than in the allied species and the teeth on their inner margins are much 

 larger. The dactylus is grooved in the usual way and bears some sharp 

 tubercles at the base of its upper surface. 



The Avalking legs are rather more slender than in P. andersonianum, 

 but the anterior margin of the projiodus, as in hat species, is double- 

 edged. The propodus of the penultimate leg is two and a half times, 

 and that of the last leg twice as long as broad. 



In the abdomen of the male (text-fig. Ic) the length of the sixth 

 segment is rather more than half its greatest breadth ; the seventh is a 

 little broader than long. 



The carapace in six specimens yields the following measurements 

 (in mm.). 



The eggs borne by an ovigerous female are very large, about 3 mm. 

 in diameter. 



Potamon hroumeanum may be distinguished from P. andersonianum 

 (i) by its more convex upper surface, (ii) by the incompletely circum- 

 scribed mesogastric areola, (iii) by the deeply bilobed front, (iv) by the 

 granulation, which, except on the chelae, is everywhere crisper — parti- 

 cularly on the antero-lateral borders of the carapace, the lower borders 

 of the orbits and the merus of the chelipedes, (v) by the smooth outer 

 surface of the chelae and larger dactylar teeth and (vi) by the more 

 slender propodus of the walking legs. From P. pealianum (Wood- 

 Mason), which it resembles in the convexity of the upper surface of the 

 carapace, P. hroumeanum is distinguished by the stronger curve and 

 sharj)er spinulation of the antero-lateral borders, by the more deeply 

 bilol)"d front and the nnich less conspicuous frontal eminences. 



