DUTCH BORNEOEXPEDITION. 



121 



Measurements in millim. : 



^ cT 



Greatest width of the eephalothorax 17| 12 



Length „ „ 13| 9| 



Distance between the external orbital angles . . 12| 9.V 



Breadth of the free border of the front . . . o^V 4^ 

 Distance, in the median line, between the free 



border of the front and the epigastric lobes . 1] l.V 



Breadth of the posterior margin of the carapace. 8,V C { 



Length of the terminal segment of the abdomen. 2^ 1^ 



, « V penultimate segment 2'^ 2 



Breadth of the anterior margin of this segment. 2| if 



» ./ „ posterior v » « » 2'| 1;^ 



Length of the antepenultimate segment .... 2 1 5 



Breadth of the posterior margin of this segment. 4.!, 3! 



Horizontal length of the larger chela .... 161 8 



» » // // fingers 9 4 



Height of the palm 8] 4 



Horizontal length of the smaller chela .... 114 7| 



,/ » » fingers 5^1 3] 



Height of the palm 4? 2;^ 



Length of the legs of the penultimate pair . . 31 22V 



» » » meropodites 9', 7', 



Breadth. » „ 3 2,V 



Length of the propodites 5] 4 J 



Breadth « „ „ 2| 1^ 



Length of the dactylopodites 7 5[ 



Potamon {Geothelphusa) Burgerij n. sp. 



(Plates 11 and 12, Fig. 14). 



One single male, captured on Mount Liang Koeboeng. 



This species that I have the pleasure to name after 

 Prof. 0. Burger of Göttingen , author of a paper on 

 Thelphusidae, has a rather thick eephalothorax, for it is 

 a little thicker than half the greatest width. The eepha- 

 lothorax is almost quadrate, little enlarged, the greatest 

 width, anteriorly, being only one and one fourth times 

 as broad as the eephalothorax is long. The upper surface 

 appears, in a lateral view, strongly convex from be- 

 fore backwards, very slightly also from side to side. The 

 semicircular groove, bounding the gastric region posteriorly, 



Notes from the Leyden ^Museum, Vol. XXI. 



