_Records of occurrence._--Specimens examined, 42: Miquihuana, 6300 ft., 7; 4 mi. N Jaumave, 2500 ft., 5; Nicolas, 56 km. NW Tula, 5500 ft., 10; Tajada, 23 mi. NW Tula, 5200 ft., 6; 8 mi. N Tula, 4500 ft., 1; 9 mi. SW Tula, 3900 ft., 13.

Additional record: Jaumave (Miller, 1924:284).

=Dipodomys ordii=

Ord's Kangaroo Rat

This species has a restricted geographic distribution in Tamaulipas, although three subspecies occur in the state; two of them occur in the extreme northeast and the other in the far west.

=Dipodomys ordii durranti= Setzer

1949. _Dipodomys ordii fuscus_ Setzer, Univ. Kansas Publ., Mus. Nat. Hist., 1:555, December 27, type from Jaumave, Tamaulipas.

1952. _Dipodomys ordii durranti_ Setzer, Jour. Washington Acad. Sci., 42:391, December 17, a renaming of _D. o.

fuscus_ Setzer, 1949.

_Distribution in Tamaulipas._--Semi-desert areas in western part of state.

The specimen examined from four miles north of Jaumave was trapped in a xeric area in which the vegetation consisted of mesquite, high palmlike yuccas, and "lechugilla." Specimens from the vicinity of Tula were trapped along bushy fence rows and adjacent to clumps of bushes and cactus, or shot at night in an area in which the soil was a sandy loam having relatively large amounts of gravel. The average weight of seven specimens from Nicolas was 50.3 (42-60) grams.

According to Lid.i.c.ker (1960:178 and in _litt._), the place called Lulu that was ascribed to Tamaulipas by Setzer (1949:550), and from which _D. o. durranti_ was reported, actually is in Zacatecas.

_Records of occurrence._--Specimens examined, 19: Miquihuana, 6200 ft., 2; 4 mi. N Jaumave, 2500 ft., 3; Nicolas, 56 km. NW Tula, 12; 8 km. N Tula, 4500 ft., 2.

Additional records (Setzer, 1949:556): Nuevo Laredo; Jaumave.

=Dipodomys ordii parvabullatus= Hall

1951. _Dipodomys ordii parvabullatus_ Hall, Univ. Kansas Publ., Mus. Nat. Hist., 5:38, October 1, type from 88 mi. S and 10 mi. W Matamoros, Tamaulipas.

_Distribution in Tamaulipas._--Known only from two islands off the barrier beach.

Weight of four adults averaged 49.2 (44-60) grams.

_Records of occurrence._--Specimens examined, 17: 33 mi. S Washington Beach, 4; 88 mi. S, 10 mi. W Matamoros, 7; 90 mi.

S, 10 mi. W Matamoros, 6.

=Dipodomys ordii compactus= True

1889. _Dipodomys compactus_ True, Proc. U. S. Nat. Mus., 11:160, January 5, type from Padre Island, Cameron Co., Texas.

1942. _Dipodomys ordii compactus_, Davis, Jour. Mamm., 23:332, August 13.

_Distribution in Tamaulipas._--Reported only from Bagdad (Hall, 1951:41).

=Dipodomys merriami atronasus= Merriam

Merriam's Kangaroo Rat

1894. _Dipodomys merriami atronasus_ Merriam, Proc. Biol.

Soc. Washington, 9:113, June 21, type from Hacienda La Parada, about 25 mi. NW San Luis Potosi, San Luis Potosi.

_Distribution in Tamaulipas._--Mexican Plateau in western part of state.

Specimens examined are tentatively a.s.signed to _Dipodomys merriami atronasus_. They differ from typical _atronasus_ as pointed out by Lid.i.c.ker (1960:177). He noted that individuals from the eastern edge of the range of _D. m. atronasus_ were slightly paler than typical specimens, but I found Tamaulipan material to be much darker, especially behind the nose and ears (blackish instead of brownish), than specimens from Aguascalientes, San Luis Potosi and Zacatecas.

Specimens examined were collected under the same conditions and in the same areas as _D. ordii durranti_. The average weight of 20 adults (11 females and nine males) was 46.6 (38-50) grams.

_Records of occurrences._--Specimens examined, 27: Nicolas, 56 km. NW Tula, 5500 ft., 16; Tajada, 23 mi. NW Tula, 5200 ft., 4; 15 mi. N Tula, 1; 8 mi. N Tula, 4500 ft., 3; 9 mi.

SW Tula, 3900 ft., 3.

Additional record: Tula (Lid.i.c.ker, 1960:178).

=Liomys irroratus=

Mexican Spiny Pocket Mouse

This species is probably the most common rodent in Tamaulipas. It was taken at almost every locality sampled and was a.s.sociated with many other kinds of rodents. Its distribution is state-wide with the exception of the extreme northwestern part. Two subspecies are represented in Tamaulipas, _L. i. alleni_, which occurs in the western side of the Sierra Madre Oriental in the southwest part of the state, and _L. i. texensis_, which occupies the rest of the range of the species in the state.

At Soto la Marina specimens were taken in dense brush, around the cultivated fields; no burrows were seen and all specimens were trapped before 10:00 p.m. On the Sierra de Tamaulipas, _Liomys_ was collected in practically all microhabitats. In the vicinity of San Fernando, individuals were trapped in a dry area in which vegetation consisted of mesquite, cactus and chollas; the ground there was covered with dry leaves and small sticks, and burrows were found near the base of the mesquite bushes. One specimen was taken near the house of a woodrat.

Two kilometers west of El Carrizo, where _Liomys irroratus_ is called "raton tuza," specimens were collected on rocks inclined at an angle of about twenty-five degrees that were covered with zacaton gra.s.s and some bushes. Some individuals were taken in a sugar cane field that was surrounded by bushes and tall gra.s.s; _Baiomys taylori_, _Sigmodon hispidus_, and _Peromyscus leucopus_ were taken in the line of traps.

One specimen was caught in a trap baited with banana.

Some dates concerning reproduction of _Liomys irroratus_ in Tamaulipas are as follows: La Pesca, May 25, one female lactating and one female pregnant with 4 embryos that measured 8 mm.; Jaumave, July 26-29, three females lactating and three pregnant females that carried 6 embryos (6 mm.), 6 embryos (15 mm.), and 5 embryos (15 mm.); Palmillas, July 23, a female with 1 embryo measuring 6 mm.; Nicolas, October 19, a female carrying 4 embryos measuring 3 mm.

=Liomys irroratus alleni= (Coues)

1881. _Heteromys alleni_ Coues, Bull. Mus. Comp. Zool., 8:187, March, type from Rio Verde, San Luis Potosi.

1911. _Liomys irroratus alleni_, Goldman, N. Amer. Fauna, 34:56, September 7.

_Distribution in Tamaulipas._--Extreme southwestern part of state.

This subspecies is easily distinguished from _L. i. texensis_ by the following features: hind foot larger, 31.5 (30-33.5) instead of 27.8 (27-29); skull longer, 34.2 (32.4-36.4) instead of 31.5 (30.0-32.5); maxillary tooth-row longer, 5.4 (5.0-5.8) instead of 5.0 (4.8-5.1); interorbital constriction relatively narrower in _alleni_.

Intergradation between _L. i. alleni_ and _L. i. texensis_ takes place at Rancho Santa Rosa (where, of the two specimens, one is conspicuously larger than the other), eight kilometers northeast of Antiguo Morelos, El Encino, and Ejido Santa Isabel. All specimens from the localities mentioned are here a.s.signed to _texensis_.

Weight of three pregnant females averaged 68.9 (64-78) grams, that of non-pregnant females, 65.6 (64-68), and that of six males 73.0 (65-80).

_Records of occurrence._--Specimens examined, 34: Villa Mainero, 1700 ft., 2; Nicolas, 56 km. NW Tula, 5500 ft., 6; Jaumave, 2400 ft., 23; 16 mi. N, 6 mi. W Palmillas, 5500 ft., 1; 14 mi. N, 6 mi. W Palmillas, 5500 ft., 2.

Additional records: Miquihuana (Goldman, 1911:56); Tula (Hooper and Handley, 1958:18).