_Distribution in Tamaulipas._--Known only from the vicinity of the type locality.

Specimens of this pocket gopher were taken in large Macabee traps, at night with the aid of a dog, and by natives using slingshots. Mounds of _H. hispidus_ were common two miles west of El Carrizo near banana trees; the mouths of burrows were four to five inches in diameter. Two females collected at this locality on April 16 and 17 were lactating.

Specimens examined of _H. hispidus_ from Tamaulipas resemble the description of _H. h. negatus_ more than that of _H. h. concavus_, and are referred, therefore, to _negatus_. I a.s.sume, on geographic grounds, that the individuals reported by Hooper (1953:5) as _concavus_ are _negatus_; they are here referred to as _negatus_. If this referral is correct, the subspecies _concavus_ probably does not occur in Tamaulipas.

_Records of occurrence._--Specimens examined, 6: Ejido Santa Isabel, 2 km. W Pan-American Highway, 2000 ft., 1; 2 km. W El Carrizo, 1; 5 km. W El Carrizo, 4.

Additional records: Rancho Pano Ayuctle (Hooper, 1953:5); Gomez Farias (Goodwin, 1953:1).

=Cratogeomys castanops=

Yellow-faced Pocket Gopher

Two subspecies of _Cratogeomys castanops_ occur in Tamaulipas, _C. c.

planifrons_ in the higher elevations of the Sierra Madre Oriental in the western part of the state, and _C. c. tamaulipensis_ on the plains of the Rio Grande.

Specimens from Miquihuana were trapped in tunnels at 6400 feet elevation. At Palmillas, individuals were trapped in an area of mesquite, other bushes and "lechuguilla." Three specimens from southeast of Reynosa were collected in traps set along the dikes of irrigation ditches. Most specimens from Nicolas were brought by natives to the collector, but some were caught in traps set in tunnels among the desert bushes.

=Cratogeomys castanops planifrons= Nelson and Goldman

1943. _Cratogeomys castanops planifrons_ Nelson and Goldman, Proc. Biol. Soc. Washington, 47:146, June 13, type from Miquihuana, 5000 ft., Tamaulipas.

_Distribution in Tamaulipas._--Higher elevations in southwestern part of state.

Specimens from four miles north of Jaumave do not differ from specimens from Miquihuana. The weights of nine females averaged 146.4 (110-210) grams; three males weighed 178, 203, and 215 grams.

_Records of occurrence._--Specimens examined, 29: Miquihuana, 6400 ft., 9; 4 mi. N Jaumave, 2500 ft., 5; Nicolas, 56 km. NW Tula, 5500 ft., 15.

=Cratogeomys castanops tamaulipensis= Nelson and Goldman

1934. _Cratogeomys castanops tamaulipensis_ Nelson and Goldman, Proc. Biol. Soc. Washington, 47:141, June 13, type from Matamoros, Tamaulipas.

_Distribution in Tamaulipas._--Known only from two localities in extreme northern part of state, but probably occurs throughout northeastern part of state.

Three specimens from three miles southeast of Reynosa are referred to _C. c. tamaulipensis_ on geographic grounds. They are tawny brown dorsally instead of cinnamon brown or pinkish cinnamon as Nelson and Goldman (1943:141) described _tamaulipensis_, and the basioccipital bone (in one male) is parallel-sided instead of wedge-shaped. Possibly this difference is owing to s.e.x; Nelson and Goldman studied only one adult, a female (the type), and the only adult seen by me was a male.

_Measurements._--An adult male (58118) from three miles southeast of Reynosa, measured as follows: 301; 81; 40; 7; condylobasal length, 57.0; zygomatic breadth, 41.2; palatal length, 36.1; breadth of rostrum, 11.8; length of nasals, 22.0; squamosal breadth, 34.0; alveolar length of maxillary tooth-row, 10.8.

_Records of occurrence._--Specimens examined, 3, from 3 mi.

SE Reynosa.

Additional record: Matamoros (Nelson and Goldman, 1934:140).

=Perognathus merriami merriami= J. A. Allen

Merriam's Pocket Mouse

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 gra.s.ses. 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

Hispid Pocket Mouse

1858. _Perognathus hispidus_ Baird, Mammals, in Repts. Expl.

Surv. ..., 8(1):421, July 14, type from Charco Escondido, Tamaulipas.

_Distribution in Tamaulipas._--Central and northern parts of state.

Two specimens examined from the vicinity of Nuevo Laredo were trapped in weeds and tall gra.s.s along an irrigation ditch that ran between desert and a cornfield. One was a lactating female (November 15) and weighed 31 grams; the other, an immature male, weighed 23 grams. A May-taken specimen from Soto la Marina possesses a broader and more ochraceous lateral line than the other three individuals examined from Tamaulipas and the Texan specimens seen.

_Records of occurrence._--Specimens examined, 4: 10 mi. S, 11 mi. E Nuevo Laredo, 600 ft., 2; Soto la Marina, 500 ft., 1; 9-1/2 mi. SW Padilla, 800 ft., 1.

Additional records (Osgood, 1900:44, unless otherwise noted): Mier; Matamoros; Charco Escondido (Baird, 1858:422); 3 mi. W Soto la Marina (Hooper, 1953:5).

=Perognathus nelsoni nelsoni= Merriam

Nelson's Pocket Mouse

1894. _Perognathus (Chaetodipus) nelsoni_ Merriam, Proc.

Acad. Nat. Sci. Philadelphia, 46:266, September 27, type from Hacienda La Parada, about 25 mi. NW Cd. San Luis Potosi, San Luis Potosi.

_Distribution in Tamaulipas._--Known only from the west side of the Sierra Madre Oriental in southwestern part of state.

Most of the specimens examined were taken in semi-arid habitats where the dominant plants were cactus, weeds and bushes.

In Tamaulipas, specimens from the southern localities (places labeled with reference to Tula) are darker than those from the two northernmost localities (Miquihuana and four miles north of Jaumave). Most measurements are about equal in the southern and northern specimens, but in some measurements southern specimens average slightly smaller than those from the north. Greatest length of skull is a case in point.

The difference in size is reflected in the weights. Average weights of nine males and nine females from southern localities are, respectively, 14.7 (12-16.5) and 13.8 (12-15.5) instead of 18.5 (17-20) and 17.0 (15-18) grams for four males and six females from the northern localities. In general, Tamaulipan specimens average somewhat smaller than those from other localities in eastern Mexico (see measurements given by Baker, 1956:238, Dalquest, 1953:107, and Osgood, 1900:53).

_Measurements._--Average and extreme measurements of six specimens (2 males and 4 females) from Miquihuana, three males from four miles north of Jaumave, and five (3 males and 2 females) from nine miles southwest of Tula are, respectively, as follows: 176.2 (163-185), ----, 170, 173, (4 specimens only) 179.0 (165-186); 99.8 (97-105), ----, 90, 93, (4 specimens only) 96.7 (88-104); 22.5 (21-23), 23, 23, 24, 22.6 (22-23); 8 (8), 8, 8, 8, 8.8 (8-9); greatest length of skull, 26.1 (25.6-26.6), 25.8, 26.5, 26.9, 25.2 (24.9-25.7); mastoid breadth, 13.3 (12.9-13.6), 13.2, 13.8, 13.6, 13.1 (12.9-13.4); interorbital constriction, 6.4 (6.1-6.6), 5.9, 6.3, 6.3, 6.3 (6.1-6.8); interparietal breadth, 7.4 (6.8-7.9), 7.7, 7.2, 7.2, 7.6 (7.3-7.9); alveolar length of maxillary tooth-row, 3.7 (3.5-4.0); 3.6, 3.5, 3.6, 3.6 (3.5-3.8).