412 Mr. O. Thomas on 



12' 7 ; palatal length 13 ; front of canine to back of m^ 10 ; 

 combined length of m^ and m^ 4"6. 



Hab. Galifari^ Sierra del Avihi, N. Venezuela. Alt. 

 6500^ 



Type. Adult male. B.M. no. 14. 7. 27. 1. Original 

 number 2, Collected 13th December, 1913, by Mr. S. M. 

 Klages. Presented by the Hon. N. C. Rothschild. 



This species is rather smaller than V. dorsalis and V. um- 

 hratus, Lyon, and differs from both by the development of 

 the inner ledges to its lower molars. Mr. Glover Allen has 

 been good enough to examine the type of V. umbratus iov me, 

 and he informs me that it has no such special development of 

 the molar ledges as is present in T^. oratus. The other species 

 with normal-sized incisors and white dorsal line are either 

 materially larger or smaller. 



Sigmomys venesier, sp. n. 



Like S. alstoni, but smaller. 



Fur rather softer than in alstoni, hairs of back about 

 11 mm. in length, the longer piles 15-16. General colour 

 above coarsely grizzled black and buffy, quite as in alstoni. 

 Sides of nose, eye-rings, and tufts at base of ear clear buff}^ 

 Undersurface grey, washed with whitish, more buffy on chest, 

 and proV)ably more completely buffy washed in older speci- 

 mens ; hairs of chin and throat white to base. Hands and 

 feet buffy whitish. Tail dark brown above, buffy whitish 

 below. 



Skull apparently only differing from that of S. alstoni in 

 its smaller size ; the buUse, however, seem to be proportionally 

 smaller, being distinctly smaller than in the Guianian 

 S. savannarum. Molars much smaller than in S. alstoni, 

 about as in savannarum. 



Dimensions of the type, somewhat immature (measured in 

 flesh) :— 



Head and body 115 mm. ; tail 80; hind foot 25; ear 18. 



Skull : greatest length 29 ; condylo-incisive length 26'5 ; 

 zygomatic breadtii 17 ; nasals 10*3 ; interorbital breadth 4' 7 ; 

 palatilar length 12*2; palatal foramina 6*4; upper molar 

 series 5, breadth of ni^ 1*9. 



Hab. El Trompillo, near Lake Valencia, N. Venezuela. 

 Alt. 1300'. 



Type. Lumature female. E.M. no. 14. 9. 1. 63. Original 

 number 63. Collected 5th May, 1914, by Mr. S. M. Klages. 

 Presented by the Hon. N. C. Kothschild. 



The species of Sigmomys are all practically alike in colour 

 and proportions. In their skulls S. alstoni of Cumana differs 



