Malacostracous Crustaceans from Malaysia. 255 



Distr. Torres Strait, Sandwich Islands, W. Australia, 

 Malay Archipelago. 



No". CCCLII. flab. Singapore. 



A young female. 



Dim. : Length 8 millim., breadth 12*5. 



XI. Genus PoTAMON, Sav. 



14. Potamon (Peritkelphusa) Biittikoferi, de Man. 



Potamon (Perithelphusa) Bilttikoferi, de Man, Notes from the Leyden 

 Museum, vol. xxi. pts. i.-iii. pp. 80-86, pi. vi. fig. 6 (1899). 



Distr. Sintang. 



No. ccxcn. Hub. Mt. Matang, 3000 feet. 



A male. Dr. de Man describes the " ischial line " on the 

 posterior maxillipedes as being parallel to the inner margin of 

 the ischial joint ; in this example it is oblique, slanting away 

 from it from before backwards. 



Dim.: Greatest length 28*5 millim., greatest breadth 35. 



15. Potamon {Perithelphusa) borneense, var. hilare, de Man. 



Potamon borneensis, var. hilaris, de Man, Notes Leyden Mus. vol. xxi. 

 pts. i.-iii. p. 71, pi. v. fig. 4 (1899). 



Distr. Sintang. 



No. XCVin. Dab. Kuching : freshwater. 



A male. 



Dim. : Greatest length 18'5 millim., greatest breadth 23. 



16. Potamon (Parathelphusa) tridentatum, 

 var. incertum, Lanchester. (PI. XII. fig. 2.) 



Potamon {Parathelphusa) tridentatum, var. incertum, Lanchester, 

 P. Z. S. Lond. (1900). 



Distr. Singapore (Botan. Gardens). 



No. cxxxvi. Hab. Kuching: presumably freshwater, but 

 I have no note to that effect. 



A male, quite agreeing with the forms I have already 

 described from Singapore ; though in this specimen the 

 lobulation of the extraorbital tooth is even more striking, 

 giving it all the appearance of having four antero-lateral teeth, 

 such that the second is truncated, while the rest are sharp. 



Dim. : Length (including rostrum) 305 millim., breadth 

 between last teeth 37' 5. 



