DUTCH BORNEO-EXPEDITION. 127 



cf 9 



Length of the terminal segment of the abdomen 2i 



„ „ „ penultimate ./ 2^ 



Breadth of the anterior margin of this segment \\ 



„ „ N posterior « » » " 2^ 



Length of the antepenultimate segment 1| 



Breadth of the posterior margin of this segment 3^ 



Horizontal length of the larger chela 12 12 



„ „ „ ., fingers 5i| 5^ 



Height of the hand • 6] 5| 



Horizontal length of the smaller hand 9 9| 



„ „ fingers 4^ 5| 



Height of the smaller hand 3| '6'1 



Length of the legs of the penultimate pair 30 34 



„ ,/ meropodites of this pair ]0 10| 



Breadth « „ „ „ ,, •• 3| 3-^ 



Length ,, „ propodites » » // 51 6 J 



Breadth „ „ „ . „ ,, 2 2 



Length of the dactylopodites « * 7 8.^ 



Potamon {Geothelphusa) bicristatum^ n. sp. 

 (Plate 12, Fig. 15). 



Two females , without eggs , were collected by Dr. Biitti- 

 kofer 0Ü Mount Liang-Koeboeng. Both specimens are almost 

 of the same size , the larger one was captured in a forest. 



This species presents some affinities to Pot. {Geothelphusa) 

 Dehaani White and Pot. {Geothelphusa) ohtusipes Stimps., 

 both from Japan ; specimens of the former are lying be- 

 fore me. 



The cephalothorax is rather much enlarged, the pro- 

 portion between the width and the length being like 7 : 

 5 ; it presents its greatest breadth along a line dividing the 

 anterior third of the upper surface from the middle. The 

 upper surface appears slightly convex anteriorly, as well 

 from before backwards as transversely, curving regularly 

 downwards towards the front, but it is flattened poste- 

 riorly. The interregional grooves are a s little developed 

 as in Pot. Dehaani. The cervical groove is distinctly 



Notes from the Leyden Museum, Vol. XXI. 



