1892. _Perognathus merriami_ J. A. Allen, Bull. Amer. Mus.
Nat. Hist., 4:45, March 25, type from Brownsville, Cameron
Co., Texas.
_Distribution in Tamaulipas._--State-wide except
southwestern part.
Most of the available specimens of _P. m. merriami_ were collected in
the semi-arid areas of mesquite and grasses. At Soto la Marina _P. m.
merriami_ was abundant in open fields surrounded by brush. One female,
collected on July 4, one mile south of Altamira was lactating. Weights
of 16 adults from Soto la Marina and that of nine adults from the
vicinity of San Fernando are, respectively: 8.2 (7-10) and 8.1 (7-9)
grams.
Specimens from Tamaulipas are darker than those examined from Coahuila
and southern Texas. A skull picked up on the barrier beach, 73 miles
south of Washington Beach, differs from all other skulls examined in
having the rostrum (3.6 mm.) and M1 (4.3) wider, auditory bullae
relatively smaller, and glenoid fossa larger (2.6 instead of less than
2.3 in specimens from Soto la Marina).
_Records of occurrence._--Specimens examined, 46: 4-4.5 mi.
S Nuevo Laredo, 900 ft., 4; 10 mi. S, 11 mi. E Nuevo Laredo,
600 ft., 2; 1 mi. S Santa Teresa, 1; San Fernando, 180 ft.,
1; 2 mi. W San Fernando, 180 ft., 14; 73 mi. S Washington
Beach, 1; 12 mi. NW San Carlos, 1300 ft., 1; Soto la Marina,
19; Ciudad Victoria, 1; 17 mi. SW Tula, 3900 ft., 1; 1 mi. S
Altamira, 1.
Additional records (Osgood, 1900:22, unless otherwise
noted): Mier; Reynosa; Matamoros; 40 mi. S Matamoros
(Hooper, 1953:5); Hidalgo; Altamira.
=Perognathus hispidus hispidus= Baird