1899-] Allen, New Rodents frpm Colombia and Venezuela. 203 



much larger, there being an average difference of about 3mm. in 

 total length, and very nearly a full millimetre in mastoid breadth. 

 This difference is shown somewhat by the external measurements, 

 inasmuch as the maximum size is greater in both sexes in H, 

 melanoleucus than in H. anomalus. The skull is also not only 

 larger in its linear dimensions, but is much more heavily built. 

 The two forms, though closely related, are thus readily separable. 



Akodon venezuelensis, sp. nov. 



Type, No, 14724, $ ad., Quebrada Secca, near Cumana, Venezuela. Col- 

 lected Dec, 10, 1898, by Mr. F. W. Urich. 



Color above yellowish brown with a slight olivaceous shade, varied with 

 blackish, the hairs being plumbeous nearly their whole length, and tipped 

 slightly with yellowish brown, producing a minutely grizzled effect, shading on 

 olive ; lower surface lighter, in general effect grayish washed with pale ochra- 

 ceous, the color of the lower parts passing insensibly on the sides into the color 

 of the upper surface; head concolor with the body ; ears medium, dark brown, 

 nearly naked on both surfaces ; tail blackish above, grayish below, covered with 

 very short hairs, through which the annulations are distinctly visible ; feet 

 dusky above, the soles of the hind feet black. 



Measurements. Type, total length, 161 mm.; tail vertebras, 60; hind foot, 

 21.5, with claws, 24 ; ear, 16. The tail in this specimen is apparently abnor- 

 mally short, due probably to injury in life, as in a series of five other specimens 

 the tail ranges in length from 70 to 77 mm. A series of 6 specimens, 3 males 

 and 3 females, all adult, measures as follows: Total length, 176 (166-189) J 

 tail vertebrae, 71 (60-77) ; hind foot (with claws), 22.3 (20-24) I ea < r i Io ( 1 5~ I 7) 



Skull, total length, 34.5 ; basal length, 23 ; zygomatic width, 19.6; mastoid 

 width, 13 ; interorbital breadth, 6 ; length of nasals, 10 ; length of palatal 

 foramina, 6.5 ; length of upper molar series, 5 ; length of lower jaw (condyle 

 to tip of incisors), 20 ; height (coronoid to angle), 8. 



Akodon venezuelensis is based on six specimens taken by Mr. F. 

 W. Urich at Quebrada Secca, in the mountains 90 miles south 

 of Cumana, Venezuela. They are all adult, and are very uniform 

 in coloration and size. Compared with A. urichi, from Trinidad, 

 it is smaller, with larger ears and a relatively longer tail, and is 

 very strikingly different in coloration, the general color above 

 being much paler and lacking the ruddy general effect seen in 

 A. uric hi. 



Akodon columbianus, sp. nov. 



Type, No. 15336, $ ad., Manzanares (alt. 3000 ft.), Santa Marta District, 

 Colombia, Sept. 6, 1899 ; Coll. H. H. Smith. 



Above dark brown minutely grizzled with strong yellowish brown, varied 



