DUTCH BORNEO-EXPEDITION. 83 



high than in the preceding species, the epistome has 

 about the same form, but the median tooth is obtuse. As 

 in that species the subhepatic region is limited off from 

 the branchial floor by a distinct transverse furrow and 

 with regard to the wrinkles and rugosities on the lower 

 surface of the cephalothorax both species agree. 



The ischial line of the external maxillipedes has the 

 same situation and direction as in the preceding form and 

 also with regard to their other characters the outer foot- 

 jaws agree, but the merus-joint is slightly less en- 

 larged with regularly rounded anterolateral angle. 



In the male of Pot. borneense var. hilaris the abdominal 

 cavity reaches as far forwards as a line uniting the outer 

 angles of the buccal frame and there are no impressions 

 or only very slight ones between these angles and the 

 end of the cavity ; in Pot. Büttikoferi, however, the cavity 

 reaches not so far forwards and the sternum bears, just 

 before its extremity, a rather deep transverse fur- 

 row between the outer angles of the buccal frame, in 

 front of which one sees, in the angle of the sternum, the 

 same transverse groove that also exists in Pot. borneense 

 var. hilaris^ and equally there are no ridges near the 

 insertion of the chelipedes. The distance between the an- 

 terior end of the ischial line of the external maxillipedes 

 and the external margin of the ischium is a little shor- 

 ter than that between the anterior extremity of the ab- 

 dominal cavity and the oblique posterior margins of the 

 buccal frame, in Pot. borneense var. hilaris, however, a 

 little broader. The sternum is smooth, punctate. The 

 male abdomen has the same form as in the preceding 

 species, but the penultimate segment is comparati- 

 vely shorter, being but very slightly longer 

 than the terminal ; the lateral margins have the same 

 form and direction in both and the punctation is the same. 



The chelipedes are very unequal, in the largest male 

 the left is the larger, in the others the right. The meri 

 project as little beyond the carapace as in Pot. borneense, 



Notes from the Leyden ^Rluseuin, \ol. XXI. 



