DUTCH BORNEO-EXPEDITION. 137 



The chelipedes of the male are almost equal ; they nearly 

 agree with those of Ses. angustifrons. lu both species the 

 inner angle of the wrist is obtuse, without a trace of a 

 tooth and the upper surface is granular. In the larger 

 male the horizontal length of the hand (Fig. IG'^') measures 

 two thirds the width of the cephalothorax. The fingers are 

 regularly tapering and have pointed tips, while those of 

 Ses. angustifrons are slightly excavated at the extremities, 

 but this may perhaps depend upon their young age. The 

 fingers are a little longer than the palm. The convex outer 

 surface of the latter is granular as also its upper margin, 

 that presents no trace of pectinated ridges ; the convex 

 inner surface bears a transverse row of granules, between 

 which and the wrist the surface is somewhat granular, 

 in Ses. angustifrons^ however, one observes a prominent 

 transverse crest with granulated edge. The dactylus is 

 somewhat granular at base, for the rest quite 

 smooth and the immobile finger is also smooth; a few 

 very short fine hairs are distributed on palm and fingers. 

 The ambulatory legs almost closely resemble those of Ses. 

 angustifrons, as is also proved by the measurements. The 

 meropodites e. g. of the penultimate pair are 3-times, the 

 propodites almost 4-times as long as broad and the ter- 

 minal joints are just as long as the propodites. The mero- 

 podites are armed with an acute tooth at the end of their 

 upper margin and show transverse rugosities on their outer 

 surface, while those of the last pair are almost smooth. 

 The dactylopodites (Fig. 16^) are slender, slightly curved 

 towards the pointed extremities; along the posterior margin 

 of these joints and of the propodites two rows of mo- 

 vable spines are observed. Along the anterior and the 

 posterior margin of the three terminal joints, short stiff 

 hairs are distributed, black at their proximal and white at 

 their distal half, but for the rest all these joints are smooth, 

 not tomentose; a few similar hairs are also seen on 

 the margins of the meropodites. One observes these hairs like- 

 wise on the ambulatory legs of 5*^5. angustifrons .1 but the 



Notes from tlie Leyden IVIiiseum, "Vol. XXI. 



