1914. _Onychomys torridus subrufus_ Hollister, Proc. U. S.
Nat. Mus., 47:472, October 29, type from Miquihuana,
Tamaulipas.
_Distribution in Tamaulipas._--West of Sierra Madre
Oriental.
The six specimens examined were collected in the desert area west of
the Sierra Madre Oriental. At Nicolas a trap set in front of a hole
held one specimen, and another was trapped beneath a brush fence that
inclosed a cornfield. _Dipodomys merriami_ and _Perognathus
penicillatus_ also were trapped beneath the fence.
A subadult from Nicolas is slightly larger (see measurements) than
either of two subadults from four miles north of Jaumave and an old
specimen from eight miles north of Tula, except in the interorbital
constriction, which is narrower. Nevertheless measurements of
Tamaulipan _Onychomys torridus_ resemble those given by Hollister
(1914:483) for _O. t. subrufus_. A specimen from Nicolas is also darker
than other individuals examined.
A female taken on July 15, four miles north of Jaumave, was lactating.
_Measurements._--Measurements of a female from Nicolas, a
male from eight miles north of Tula, and a female and a male
from four miles north of Jaumave are as follows: 158, 147,
145, 144; 59, 58, 55, 55; 22, 21, 22, 22; 21, 20.5, 18, 18;
condylobasal length, 24.4, 23.1, 23.9, 23.7; interorbital
constriction, 4.1, 4.4, 4.3, 4.5; length of nasals, 10.6,
10.5, 10.5, 10.1; length of maxillary tooth-row, 3.8, 3.6,
3.7, 3.7; breadth of braincase, 11.8, 11.3, 11.3, 11.0;
weight in grams, 32.5, 26.0, 25.0, 25.0.
_Records of occurrence._--Specimens examined, 6: 4 mi. N
Jaumave, 2; Nicolas, 56 km. NW Tula, 5500 ft., 2; Tajada, 23
mi. NW Tula, 5200 ft., 1; 8 mi. N Tula, 4500 ft., 1.
Additional records (Hollister, 1914:475): Miquihuana;
Jaumave.
=Sigmodon hispidus=