DUTCH BORNEO-EXPEDITION'. 113 



Width of the orbits 3 



Height « » , 2 



Distance, in the median line, between the frontal margin and the epi- 

 gastric lobes 1^ 



Length of the terminal segment of the abdomen 2j- 



„ f, „ penultimate segment 2J. 



Breadth of the anterior margin of this segment 2 



» » » posterior » » „ » 2-i- 



Length of the antepenultimate segment 1^ 



Breadth of the posterior margin of this segment 3* 



Horizontal length of the larger hand ]0.^- 



» „ ff „ fingers 5-J 



Height of the palm 5 



Horizontal length of the smaller chela "j- 



., „ fingers 4| 



Height of the palm 2i 



Length of the legs of the penultimate pair 25 



./ » ./ meropodites of this pair 7| 



Breadth , „ ., „ „ ., 2?, 



Length of the propodites of this pair 4^ 



Breadth „ ,. « . „ 1 ^ 



Length of the dactylopodites of this pair 5-| 



Breadth „ „ . „ „ „ t 



Potamon (Geofhelphusa) hendersonianuin, n. sp. 

 (Plate 11, Fig. 13). 



Two males and four females, one of whicli is ova-bearing, 

 were collected, October 1893, by Dr. Hallier at the top of 

 Mount Damoes, Sambas, at an altitude of 1100 — 1800 

 meter. 



One very young male, collected by Dr. Nieuwenhuis, 1893, 

 at the foot of Mount Damoes. 



This species , that I have the pleasure to dedicate to 

 Prof. ,1. R. Henderson of Madras, belongs to the subgenus 

 Geothelphusa, because the post-frontal ridge is only repre- 

 sented by the more or less distinct, epigastric lobes and 

 it differs from allied species by the epibranchial teeth 

 wanting completely. 



The cephalothorax is little enlarged, the greatest width 



Notes from the Leyden M.u.seum, Vol. >CXI. 



8 



