Specimens examined.—Total 179 as follows: Tamaulipas: Sierra Madre Oriental, 5 mi. S, 3 mi. W Victoria, 1900 ft., 2; 8 mi. S, 6 mi. W Victoria, 4000 ft., 37; Sierra de Tamaulipas, 2000 ft., 8 mi. S, 11 mi. W Piedra, 13. San Luis Potosi: Villar, 11 (USNM); 10 km. E Platanito, 19 (LSU); 8 mi. E (by road) Santa Barbarita, 12 (LSU); Agua Zarca, 3 (LSU); 6 km. NE Cd. Maíz, 13 (LSU); Pendencia Region (Puerto Lobos), 1 (LSU); Pendencia, 2-1/2 mi. N Puerto Lobos, 5 (LSU); 3 km. SW Sán Isidro, 15 (LSU); Cerro Coneja Region, Llano Coneja, 6100 ft., 2 (LSU); Xilitla, 4 (LSU). Hidalgo: 10 mi. NE Jacala, 5050 ft., 7; Regla (Sán Miguel), 2250 m., 4; Arroyo de las Tinajas, 2370 m., 9.5 km. SSW Tulancingo, 1; 10 mi. NW Apam, 7750 ft., 1. Veracruz: 3 km. N Zacualpan, 6000 ft., 1; 3 km. W Zacualpan, 6000 ft., 12; 2 km. N Los Jacales, 7500 ft., 8; 6 km. WSW Zacualpilla, 6500 ft., 5. Tlaxcala: Mt. Malinche, 3 (USNM).
Peromyscus boylii beatae Thomas
1903. Peromyscus beatae Thomas, Ann. Mag. Nat. Hist., ser. 7, 11:485, May, type from Xometla Camp, Mt. Orizaba, Veracruz.
Geographic distribution.—East side of the Sierra Madre Oriental in Veracruz, from Jalancingo south to Xuchil.
Diagnosis.—Size large for the species; tail no shorter than head and body (100-114.8%); dorsum dark (near Prout's Brown or Mummy Brown middorsally, Clay Color on sides); supraorbital border rounded; anterior palatine foramina long.
Comparisons.—P. b. beatae differs from other subspecies of P. boylii by the combination of large size, long tail, and dark color.
Remarks.—Thomas (1903:485) described P. beatae on the basis of five specimens from Xometla Camp (lat. 18° 59' N, long. 97° 10' W) and one juvenile from Santa Barbara Camp, both on the Volcán de Orizaba, Veracruz. Thomas thought that beatae was related to aztecus, but the differences relied on by him to distinguish the two are the same as those that distinguish aztecus from boylii. Osgood (1909:153) placed beatae in synonymy under P. b. levipes because Mount Orizaba (type locality of beatae) is "relatively very near" Mount Malinche (type locality of levipes), and Thomas had not compared beatae with levipes. Xometla, on the east side of the Volcán de Orizaba, is approximately 56 miles east of the Tlaxcalan part of Mount Malinche and is situated where the Tropical Life-zone begins, whereas Mount Malinche is in the Austral Life-zone on the Mexican Plateau; the difference in habitat between the two places is great. Topotypes of levipes differ from two topotypes of beatae in the same fashion as do other specimens of levipes (from San Luis Potosí) from other specimens of beatae (from Veracruz). Unfortunately, the topotypes of beatae lack external measurements and are subadults, but their coloration agrees with that of other specimens that are here referred to beatae.
Hall and Kelson (1959:634, map 364) incorrectly mapped the distribution of levipes in Veracruz. There are at least two places named Xuchil in the state of Veracruz and Hall and Kelson (loc. cit.) unfortunately plotted the one at lat. 20° 42' N, long. 97° 42' W whereas the specimens actually were collected at the Xuchil on the pleateau south of the Volcán de Orizaba (18° 53' N, 97° 14' W) in the west-central part of Veracruz. The specimens from Xuchil are P. b. beatae.
Intergradation in color between the two subspecies levipes and beatae is seen in specimens from Jalapa and Zacualpan (3 km. N, also others from 3 km. W), Veracruz. Intergradation between these two subspecies possibly will be found elsewhere along the Sierra Madre Oriental.