DUTCH BORNEO-EXPEDITION. 59 



No9 122, 126 and 134 belong to the blue-bellied type, 

 Nos 5, 11, 52, 91 and 269 have the belly red. In our 

 collection there is a great number of specimens represent- 

 ing both varieties and also the intermediate stages. (Cf. 

 my List of specimens of squirrels in the Leyden Museum, 

 N. L. M. 1883, p. 133, sub Sciurus plantani). 



Rhcithroselurus. 



JRheithrosciurus macrotis Gray. 



194. Adult female. Skin and skull. Mount Liang 

 Koeboeng. 24. 4. 1894. B. 



Iris brown. 



This wonderful squirrel has been figured in the P. Z. S. 

 1856, pi. 46, its skull however has never been studied and 

 nowhere figured although it is the most interesting part 

 of the animal. No other squirrel has a similar dentition , 

 meanwhile the shape as well as its size differ from all 

 what is known among squirrels , as will be evident when 

 comparing the skull , figured on plate 3, with other skulls ; 

 it will be sufiBcient to point out more closely a couple of 

 peculiar characteristics. The skull is larger than that of 

 any other squirrel, the nasal bones are very elongate, the 

 distance between the upper incisors and the molars is 

 peculiarly great , the length of the molars is a good deal 

 smaller than that of the same organs in Sciurus bicolor , 

 the shape of the lower jaw is quite different from that of any 

 other squirrel , but the most characteristic are the incisors , 

 both in upper and lower jaw. Their anterior surface namely 

 bears a number of deeply carved ridges, about ten, so 

 that their cutting edge is saw-shaped , an arrangement not 

 recorded among the other mammals. 



"Von dieser grossen, auf der Erde lebenden Art haben 

 wir ein einziges Exemplar im Bergwalde am Liang Ku- 

 bung erbeutet (780 M. über Meer in der Nahe der Station 

 »Punan-Grotte"). Beim Gehen tragt das Thier den Schwanz 

 oft über den Rücken aufgeschlagen." B. 



Notes from the Leyden Museum, Vol. XIX. 



