52 FIELD MUSEUM or NATURAL HISTORY ZOOLOGY, VOL. X. 



scarcely marked." Mr. Thomas has kindly compared one of our 

 specimens with the type without finding differences that would warrant 

 separation. 



Microxus bogotensis Thomas. Bogota Microxus. 



Eighteen specimens, Paramo de Tama, head of Tachira River, 

 Colombia and Venezuela. 



These mice were taken in small numbers in the depths of the forest 

 on the Colombia side of the Tachira but were much more common in 

 open grassy swamps on the slopes of the Venezuela side of the river. 

 In fresh specimens, the pointed noses and rather small ears combined 

 with the dense dark-colored fur, give them quite a soricine appearance. 

 Their identification as M. bogotensis has been substantiated by the 

 submission of specimens to Mr. Thomas of the British Museum. Aver- 

 age external measurements of ten adults are : Total length 1 50 (145-156) ; 

 head and body 85.4 (82-91) ; tail vertebras 63.4 (61-67) ! hind foot (c. u.) 

 19.1 (18-20). 



Zygodontomys thomasi Allen. Thomas Zygodontomys. 



Seven specimens, El Panorama, Rio Aurare (5) and Empalado 

 Savannas (2). 



Although trapping was done in various other places, specimens of 

 this species were taken only on the low ground near the dry bed of the 

 Rio Aurare among loose sticks, logs, and drift. The majority of them 

 are practically indistinguishable from typical thomasi. Two individuals, 

 although apparently mature, are decidedly smaller than the others, 

 but it is difficult to believe this to be of specific significance. 



Although formerly associated with Oryzomys, the species of this 

 genus seem to have much in common with A kodon, but their true posi- 

 tion in the involved series of Neotropical rodents is doubtless yet to be 

 ascertained. 



Zygodontomys thomasi sanctaemartas Allen. Santa Marta Zygo- 

 dontomys. 



Two specimens, El Guayabal, 10 miles N. of San Jose de Cucuta, 

 Colombia. 



These mice, caught at the edge of a cornfield after much fruitless 

 trapping, were practically the only small mammals secured at this 

 locality. The single adult male agrees in color with lighter examples 

 of sanctcemartcB from the type locality, but its skull is very large and 



