494 Mr. 0. 1 homas on some 



L. — Notes on some S.-American Muridee. 

 By Oldfield Thomas. 



I. On three new Species from the Lower Amazon. 



Thanks to the kindness of Dr. E. A. Goeldi, of the Para 

 Mi;seuni, I have been entrusted with a small collection of 

 Bats and Rodents collected along the Lower Amazon. 



Among these there are specimens of the three following 

 new species of Muridae. The typical specimen of each of 

 them has been presented by Dr. Goeldi to the British 

 Museum. 



Oryzomys Goeldi^ sp. n. 



Allied to 0. laticeps, Lund, with some specimens of which 

 it agrees closely in colour and proportions, but much smaller 

 in actual size. 



Fur rather short, close, and straight, 6 or 7 millim. long 

 on the posterior back. 



General colour dull brown, tinged with dark buff, which is 

 clearer on the flanks. Belly greyish white, well defined, the 

 bases of the hairs slaty grey, the tips white or buffy white. 

 Ears of medium length, thinly haired, brown. Hands and 

 feet dull whitish ; the metapodials and digits alike. Tail 

 rather longer than the head and body, slender, very thinly 

 haired ; pale brown above and below. 



Skull very similar to that of 0. laticeps, apart from its 

 smaller size. Nasals evenly narrowing backwards. Inter- 

 orbital region level transversely, its edges square but not ridged, 

 although posteriorly ridges are traceable along the parietals 

 to the outer corners of the interparietal. General profile 

 of skull evenly curved, convex from tip of nasals to back of 

 interparietals. Anterior palatine foramina about equal in 

 length to the molar series. Posterior nares square, tiie ptery- 

 goids parallel. 



Dimensions of the type (taken as a spirit-specimen before 

 skinning) : — 



Head and body 96 ; tail 104 ; hind foot 26; ear 15. 



Skull: basilar length 225; greatest breadth 14"5 ; nasals 

 11-8 X 3-5 J interorbital breadth 5; interparietal 3-7 x 9-6 ; 

 palate length from henselion 13; diastema 8; anterior pala- 

 tine foramina 4*6 ; length of upper mohir scries 4'5. 



JIab. Itaitiiba, Tapajoz, Lower Amazon. 



Type. Female. B.M. No. 97. 4. 1. 1. 



This interesting little species, which is evidently a local 



