90 CRUSTACEANS OF THE 



Measurements iu mm. : 12 3 4 5 



cf c^ ^ cf 9 



Greatest width of the cephalothorax. . . . 36^ 33^ 32^ 31| 28 



Length „ ,, „ ... 29 27 26 26 23 



Distance between the ext. orbital angles . . 22| 20i 20 J 194 ^"\ 



» the tips oftheepibranchial teeth 321 aOi 29J- 28^ 25^ 



•/ H the tip of the epibranchial tooth 



and the external orbital angle .... 6 5|. 5^ 5i 4^ 3^ 2 



Breadth of the free border of the front . . 9^ 9 8i 8^ 7| 6 4^ 

 Distance between the free border of the front 



near its outer angles and the epigastric lobes 3i 3 3 3i 3 2^ 2 

 Distance between the anterior frontal margin 



and the posterior boundary of the gastric 



region 19 17^ 16^ 17 15 9 



Width of the posterior margin of the carapace. 16 15 14^ 14 14|. 11^- 8 



Width of the orbits 6 51^ 5J- 5i. 4i 4 3 



Height of the orbits 4 3^ 3^ 3'. 3-^ 2^ 2 



Distance between the free border of the front 



and the tip of the median tooth of the 



epistorae 4J 4| 3| 3| 3» 3 2 



Length of the terminal segment of the male 



abdomen 5^ 5 4^ 4^ 



Length of the penultimate segment. ... S-J 6^^ 5 5i 



Breadth of the anterior margin of this segment. 4.^ 4| 4 4 



,/ ,/ posterior „ „ „ „ 41 4^ 4 4 



Horizontal length of the larger chela. . . 30 26 26 27 17 



» , fingers 16i 13J 14 14^ 9^ 



Height of the larger chela at the articulation 



of the fingers 121- 12 12^ 12^ 64 



Length of the meropodites . . -^ 16^ 15^ 14^ 14-J- 13^ 

 Breadth „ „ „ . . . "g 'S „• 5 ' 5^ 5^ 5^ 4| 

 Length of the propodites ... 1=^ „ .S 9 9 8 8 7.! 



Breadth-, „ „ in the middle %,\° 4, 4 3^ Z\ 2>\ 



Length of the dactylopodites . . '=s 11 10 ^\ 10 9 



NO 1—6 Nanga Raoeu, W 7 Poetoes Sibau. 



Potamon (Perithelphusa?) sp. 

 (Plate 7, Fig. 7). 



One male collected, May 1894, on the Liang-Koeboeng 

 Mountains. 



This specimen, certainly a quite young one, almost 

 fully agrees with Pot. silvicola, especially when it is com- 

 pared with the young male from Poetoes Sibau. It differs, 



Notes from, the Leyden Museum, Vol. XXI. 



