Additional record: Altamira (Goldman, 1910:29). =Neotoma micropus micropus= Baird 1855. _Neotoma micropus_ Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:333, April, type from Charco Escondido, Tamaulipas. _Distribution in Tamaulipas._--From Soto la Marina northward. The weight of five males and four females from Soto la Marina averaged, respectively, 256.4 (210-317) and 233.0 (195-274) grams. A specimen (56924) from La Pesca differs from all other specimens of _N. micropus_ examined in being smaller, having a conspicuously shorter rostrum, broader intraorbital canal, and lower broader braincase. External measurements of this specimen are as follows: 347; 155; 39; --. Its cranial measurements are: greatest length, 44.8; basilar length, 34.3; zygomatic breadth, 23.6; interorbital constriction, 6.2; incisive foramina, 6.5; length of maxillary tooth-row, 8.7; width of mesopterygoid fossa, 4.1. _Records of occurrence._--Specimens examined, 58: 4 mi. SW Nuevo Laredo, 900 ft., 14; 4-1/2 mi. S Nuevo Laredo, 1; 3 mi. SE Reynosa, 1; 3 mi. S Matamoros, 2; 33 mi. S Washington Beach, 1; San Fernando, 180 ft., 1; 7 km. S, 2 km. W San Fernando, 2; 12 mi. NW San Carlos, 1300 ft., 4; 9-1/2 mi. SW Padilla, 800 ft., 3; 3 mi. N Soto la Marina, 3; Soto la Marina, 500 ft., 12; 4 mi. N La Pesca, 3; 1 mi. E La Pesca, 1; La Pesca, 2; 3 mi. NE Guemes, 1; 7 mi. NE Cd. Victoria, 1; Cd. Victoria, 6. Additional records (Goldman, 1910:28, unless otherwise noted): Nuevo Laredo; 10 mi. S Nuevo Laredo (Booth, 1957:15); Camargo; Matamoros; Bagdad; 40 mi. S Matamoros (Hooper, 1953:9); Sierra San Carlos (El Mulato, Tamaulipeca) (Dice, 1937:254); San Fernando (J. A. Allen, 1891:224); Forlón. =Microtus mexicanus subsimus= Goldman Mexican Vole 1938. _Microtus mexicanus subsimus_ Goldman, Jour. Mamm., 19:494, November 14, type from Sierra Guadalupe, southeastern Coahuila. _Distribution in Tamaulipas._--Reported only from mountains near Miquihuana (Goldman, 1938:495). =Canis latrans= Coyote In Tamaulipas two and possibly three subspecies of _Canis latrans_ occur. _C. l. texensis_ is known only from the northwesternmost part of the state, and _C. l. microdon_ occurs from Camargo south to Nicolás. Hall and Kelson (1959:845) guessed that _C. l. cagottis_ would be found in the southern third of the state; as yet specimens from there have not been obtained and the subspecific identity of the coyotes there, if any are present, remains in doubt. =Canis latrans microdon= Merriam 1897. _Canis microdon_ Merriam, Proc. Biol. Soc. Washington, 11:29, March 15, type from Mier, on Río Grande, Tamaulipas. 1932. _Canis latrans microdon_, Nelson, Proc. Biol. Soc. Washington, 45:224, November 26. _Distribution in Tamaulipas._--Probably state-wide, reported only from the northern half of the state.