234 Elliot New Mammals from Mexico and San Domingo. 



and feet whitish-gray; ears externally black on anterior half, gray on 

 posterior. 



Measurements. Total length, 235 ; tail vertebrae, 91 ; hind foot, 27 ; ear, 

 21. Skull: Occipito-nasal length, 38 ; Hensel, 30; interorbital width, 9; 

 zygomatic width, 21; mastoid breadth; 17; palatal length, 1(>; length of 

 nasals, 12; width of rostrum posteriorly, 7; length of upper toothrow, 6; 

 length of mandible to tip of incisors, 23; length of lower toothrow, 6. 



Remarks. Five specimens of this chipmunk were obtained by Messrs. 

 Heller and Barber at Coyotes, about 20 miles to the west of Durango City. 

 While resembling somewhat the two forms to the westward of the Sierra 

 Madre, as might be expected, the present form attracts attention by its 

 darker and more reddish coloration, especially on the back and rump, by 

 the rufous hue of the pale dorsal stripes ; by the plumbeous underparts 

 and by the chestnut color of the tail beneath. It appears to be entitled to 

 specific recognition, and may not be placed with either of its near relations. 

 For comparison, I have had Dr. Allen's types and series of T. bulleri and 

 T. durangse. 



Rhithrodontomys amoenus sp. nov. 



Type from Reforma, Oaxaca, Mexico. Field Columbian Museum. Col 

 lector's No. 3823. 



General characters. Somewhat similar to R. helvolus but smaller and dif- 

 erently colored 



Color. Fore part of back, cheeks and shoulders pale ochraceous buff; top 

 of head, lower partof back, rump and flanks dull ochraceous rufous, tinged 

 with hazel ; underparts, hands and feet white ; tail brownish above, white 

 beneath. 



Measurements. Total length, 148 ; tail vertebrae, 81 ; hind foot, 8.5. Skull : 

 Total length, 20; Hensel, 14; zygomatic width, 10; interorbital width, 8; 

 palatal length, 8; length of nasals, 6; of upper toothrow, 4 ; of mandible, 

 12; of lower toothrow, 4. 



Remarks. In color, this species does not closely resemble any described, 

 although it belongs to the group represented by R. helvolus and is 

 perhaps nearest to that form, but it is considerably smaller, as the measure 

 ments show, with quite a different style of coloration. A single specimen 

 was procured by Messrs. Heller and Barber. Another example is in the 

 collection of the Biological Survey. 



Orthogeomys cuniculus sp. nov. 



Type from Yautepec, Oaxaca, Mexico. Field Columbian Museum. Col 

 lector's No. 3878. 



General characters. Size medium ; no nasal pad ; hair scanty ; pelage 

 rather harsh, neither bristly nor soft; tail long, naked ; skull heavy ; zygo 

 mata slender and narrowest posteriorly ; nasals long. 



Color. General color over all the body Vandyke brown ; hairs on under 

 parts and limbs very scanty, the flesh color of the skin being chiefly notice 

 able; hands, feet and tail flesh color. An immature specimen is Front's 

 brown, somewhat darker than the adult, the fur being more woolly. 



Measurements. Total length, 330; tail vertebrae, 95; hind foot, 44 ; ear, 7. 



