KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 57. N:0 2. 



47 



Type: Adult female collected at Sakerat, Eastern Siarn, January 1912. 



Skull measurements (for comparison I also record the skull measurements of a 

 specimen of Rattus ephippium Jent. from the Baram River, Borneo, and of a specimen 

 of Rattus concolor Blyth from Teluk Anson, the Malay Peninsula): 



Skull measurements 



R. saker- 

 atensis 



R. ephip- i D , 



■ r R. concolor. 

 pium 



Greatest length 



Condylus to gnathion 



Basicranial length 



Zygomatic width 



Width of brain case 



Least interorbital width 



Breadth between meatus auditiva . . . 



Length of nasals mesially 



Breadth of nasals anteriorly 



Breadth of nasals posteriorly 



Diastema 



Palatal length from henselion 



Length of foramina incisiva 



Combined breadth of foramina incisiva 

 Breadth between bullae (anteriorly) . . 



Breadth of palate betwoen m' 



Maxillary toothrow 



9 



31,0 mm. 

 28,0 » 

 25,4 

 13,8 

 14,0 » 



4,9 

 12,0 

 10,7 » 



3,3 



0,8 » 



7,0 

 1 1 ,6 » 



4,1 



1,8 » 



3,0 



1,8 



."'.0 



29,0 

 26,7 

 24,7 

 12,8 

 12,3 



4,1 

 12,0 

 10,3 



2,5 



7,2 

 12,6 

 3,2 

 1,5 

 1,6 

 2,6 

 4,1 



30.4 mm. 

 27,7 » 



25.5 » 



13,5 » 

 12,5 



4.7 » 



10,5 » 



3,0 » 



1,4 » 



7,1 



12,9 

 5,3 

 1,6 

 2,1 



2,1 



4.8 I 



Cannomys minor lönnbergi subsp. n. 



In the Annals and Magazine of Natural History, vol. 16 No. 91. 1915 p. 56 — 61 

 and vol. 16 No. 94. 1915 p. 313 — 317 Oldfield Thomas has given a review of some of 

 the Asiatic Bamboo-Rats. He recognises three different groups all of which ha ve before 

 been united under the generic name of Rhizomys. 



The Siamese form formerly known as Rhizomys minor Gray. is now called Canno- 

 mys minor. 



The Natural History Museum in Stockholm is in possession of two specimens of a 

 Bamboo-Rat collected by myself in Eastern Siarn 1912. When writing my account of 

 the Mammals obtained by the Expedition (Arkiv för Zoologi, Band 8. N:o 23. 1914) 

 I referred these two specimens to Rhizomys minor Gray. with the remark that »they 

 are rather smaller than typical Rhizomys minor Gray. The fur is also of a somewhat dif- 

 fering colour, being bluish grey, instead of ashy brown». 



Concerning the characteristics of the genus Cannomys Oldfield Thomas remarks 

 that »on the analogy of other burrowing rodents, one might ha ve expected to find a con- 

 siderable number of plumbeous individuals in all districts, but curiously enough, these 

 only occur in a single race — that of the Shan States plateau — ». 



Tliis race has been recently described by Thomas under the name of Cannomys 

 castanens plumbescens. 



