406 CRUSTACEANS OF THE 



known congeners at first sight by the extraordinarily long 

 and slender ambulatory legs and I will therefore firstly 

 indicate the differences between the Indian species and 

 that from Central Borneo. 



Pot. mistenianum W.-Mas. was described after a single 

 adult female, the carapace of which is 48 mm. broad; 

 the cephalothorax of the largest specimen from Central 

 Borneo is not yet half as broad, but, as was already re- 

 marked, our specimens are perhaps not yet fully deve- 

 loped. The two females show an epibranchial tooth, obtuse 

 and small, but the males present only a trace of it; the 

 epibranchial teeth of Pot. austenianum, however, are de- 

 scribed as » extremely salient". The epibranchial teeth pass 

 backwards as crests that in the species from Assam are 

 prominent and dentate, in the Borneo specimens, however, 

 only finely denticulate or granulate. The epibranchial 

 teeth are situated comparatively more back- 

 wards, farther distant from the external orbi- 

 tal angles than in the Indian species so that the extra- 

 orbital tooth appears larger and the postfrontal ridge 

 placed more backwards. The post-frontal ridge runs as in 

 Pot. mistenianum', the epigastric lobes that are finely gra- 

 nulate and confluent with the protogastric regions, are 

 somewhat advanced, the mesogastric furrow between them 

 is deep, but not continued untill the cervical groove. The 

 epigastric lobes are somewhat oblique and separated by 

 shallow furrows from the contiguous portions of the post- 

 frontal ridge. These external portions are granular but do 

 not reach until the epibranchial teeth. The mesogastric 

 area is bounded in the Indian species by distinct furrows 

 from the rest of the gastric region; these furrows are 

 wanting completely in Pot. Melanippe. The external 

 portions of the supraorbital margins are more oblique, 

 as may be seen by comparing my figures with those of 

 Wood-Mason, and the orbits are little broader 

 than high, those of Fat. austenianum appear to be only 

 half as high as broad (Wood-Mason, 1. c. fig. 2). The 



Notes from the Leyclen Museum , "Vol. XXI. 



