1887. Hesperomys (Vesperimus) taylori Thomas, Ann. Mag. Nat. Hist., ser. 5, 19:66, January, type from San Diego, Duval Co., Texas.
1907. Baiomys taylori Mearns, U. S. Nat. Mus., Bull. 56:381, April 13.
Distribution in Tamaulipas.—All of state, except southwestern desert part.
The species of this genus have been revised recently by Packard (1960) and the specimens from Tamaulipas are arranged according to his systematic findings. The weight of 35 specimens labeled with reference to Altamira are 7.6 (6.0-9.0) grams; 15 from Jaumave weigh 6.9 (6.0-9.0) grams. Pregnant females were collected as follows: February 22, Ejido Santa Isabel, 3 (embryos x 4 mm. in crown-rump length); March 2, Rancho Pano Ayuctle, 6 x 16; July 9, six miles north and six miles west of Altamira, 1 x 4; July 28 and 29, Jaumave, 2 x 8 and 3 x 9. The average number of embryos was 2.8 (1-5).
Records of occurrence.—Specimens examined, 83: 4 mi. N La Pesca, 1; Cd. Victoria, 3; Jaumave, 2400 ft., 17; Ejido Santa Isabel, 2 km. W Pan-American Highway, 2000 ft., 7; Rancho Pano Ayuctle, 25 mi. N, 3 km. W El Mante, 300 ft., 4; Rancho Pano Ayuctle, 6 mi. N Gómez Farías, 300 ft., 1; Río Sabinas, 8 km. N El Encino, 400 ft., 1; 2 km. W El Carrizo, 2; 6 mi. N, 6 mi. W Altamira, 33; 5 mi. N, 5 mi. W Altamira, 4; 1 mi. S Altamira, 3; 16 km. N Tampico, 4; 10 mi. NW Tampico, 1; 7 mi. S Altamira, 1; 1 km. N Tampico, 1.
Additional records (Packard, 1960:654): Camargo; Charco Escondido, 20 mi. S Reynosa; Matamoras (= Matamoros); Hidalgo; 29 mi. N Cd. Victoria; Antiguo Morelos.
Onychomys leucogaster longipes Merriam
Northern Grasshopper Mouse
1889. Onychomys longipes Merriam, N. Amer. Fauna, 2:1, October 30, type from Concho County, Texas.
1913. Onychomys leucogaster longipes, Hollister, Proc. Biol. Soc. Washington, 26:216, December 20.