From 1930 on, several expeditions yielded new information about the native mammals. In that year L. B. Kellum visited the Sierra San Carlos. The results were reported by Dice (1937). Another important collection from Tamaulipas was made by Marian Martin in the area of Gómez Farías. Mammals collected by her were reported by Goodwin (1954). Hooper (1953) also reported specimens from Gómez Farías but included in his report records of mammals collected in other areas as well. In 1950 E. R. Hall and C. von Wedel made a trip to the barrier beach in the northeastern part of the state and collected several kinds of mammals among which three were described as new by Hall (1951). The report here presented is based upon specimens in the Museum of Natural History of The University of Kansas that were collected mainly by the persons named beyond. Gerd H. Heinrich and his wife Hilda collected in 1952 and 1953 in the areas around Miquihuana, Ciudad Victoria, Soto la Marina, Sierra de Tamaulipas, and Altamira. W. J. Schaldach collected in 1949 and 1950 in the Sierra Madre Oriental south of Ciudad Victoria; he returned to Tamaulipas in 1954 in company with V. Grissino and worked in the Sierra Madre Oriental south and north of Ciudad Victoria. In 1961 P. L. Clifton and J. H. Bodley collected in the northwestern part of the state and in the western part, around Tula, Nicolás, and Tajada. Some students and staff members of the Museum have occasionally collected in Tamaulipas. As a result of all the mentioned expeditions and others, 32 species and subspecies have been described with type localities in Tamaulipas. They are: Altamira _Lepus californicus altamirae_ Nelson _Sciurus aureogaster aureogaster_ (Cuvier) (by restriction) _Sciurus deppei negligens_ Nelson _Geomys tropicalis_ Goldman Antiguo Morelos, 8 mi. N of _Tadarida laticaudata ferruginea_ Goodwin Brownsville (Texas), 45 mi. from _Scalopus inflatus_ Jackson Charco Escondido _Perognathus hispidus hispidus_ Baird _Neotoma micropus micropus_ Baird El Carrizo _Peromyscus ochraventer_ Baker Gómez Farías _Heterogeomys hispidus negatus_ Goodwin Hacienda Santa Engracia _Oryzomys fulvescens engracia_ Osgood Jaumave _Dipodomys ordii durranti_ Setzer La Pesca, 1 mi. E of _Spermophilus spilosoma oricolus_ Alvarez Matamoros _Cryptotis parva berlandieri_ (Baird) _Lasiurus intermedius intermedius_ (H. Allen) _Dasypus novemcinctus mexicanus_ Peters (by restriction) _Cratogeomys castanops tamaulipensis_ Nelson and Goldman _Felis yagouaroundi cacomitli_ Berlandier Matamoros, 88 mi. S, 10 mi. W of _Lepus californicus curti_ Hall _Dipodomys ordii parvabullatus_ Hall _Sigmodon hispidus solus_ Hall Mier _Canis latrans microdon_ Merriam Miquihuana