DUTCH BORNEO-EXPEDITION. 75 



of the front is broad. The anterior margin of the epistorae, 

 the surface of which is smooth , is as far distant from the 

 frontal margin as from the tip of the triangular pro- 

 cess that the posterior margin of the epistome sends back- 

 wards and downwards ; on either side of this median tooth , 

 the smooth posterior margin shows still another smaller, less 

 prominent tooth, so that it is twice notched on each side. 



The subhepatic area is limited ofi from the branchial 

 floor by a finely granular transverse line and both regions 

 are beset with oblique raised lines or rugae, that are also 

 finely granular and as usual reach to the postero-lateral 

 margins. The groove between the hepatic region and the 

 branchiostegite is rather deep, especially anteriorly; one 

 observes on the latter, near that groove, a few oblique 

 rugations, but it is for the rest smooth. 



The ischium-joint of the outer foot-jaws appears finely 

 punctate under a magnifying glass, the longitudinal furrow 

 on it is deep and runs close to and parallel 

 with the inner margin. The merus-joint is some- 

 what broader than long, its antero-external angle is obtusely 

 rounded ; this joint appears also punctate under the lens 

 and somewhat rugose at its postero-external angle, the 

 punctatiou , however, is in some individuals rather indistinct. 



The sternum and the abdomen of the male are smooth , 

 though appearing finely punctate under a lens. There is 

 at the anterior extremity of the sternum, between the pos- 

 terior margins of the maxillipedes, a transverse fur- 

 row or impression, but there are no ridges on the 

 sternum near the insertion of the chelipedes. In this 

 species the distance between the anterior extremity of the 

 ischial furrow and the outer margin of the ischium-joint 

 appears a little broader than the distance between the 

 anterior extremity of the abdominal cavity and the posterior 

 margin of the buccal frame. Prof. Hilgendorf made me 

 acquainted with this character. 



The male abdomen bears some resemblance to that of 

 Potamon (Geothelphusa) loxophthalmufn, de M. (deMan,in: 



Notes from the Leytleii JMuseiim, Vol. ^XI. 



