E.V. Miller 1940 Perognathus merriami March 24 400'+ elev. 38 mi. S of Nuevo Laredo, in Nuevo Leon, Mexico. Took one ♀, us embryos in mouse traps on rocky ground and in open brush. Took also Peromyscus leucopus and Dipodomys merriami. April 5 Elevation about 100 ft., 24 mi. ESE Reynosa, Tamaulipas, Mexico. Took 3 ♂ P. merriami in traps. Habitat-fine grey brown soil; high mesquite and prickly pear cactus. April 5 550± ft. 31 mi. FNE Bravo, Nuevo Leon, Mexico. Took 4 of P. merriami in live mouse traps set along old road and bailed with bird seed. Habitat- very thick prickly pear cactus with little brush. Fine sandy soil. April 8 & 9 Elevation less than 100 ft. 5.7 mi. S Matamoros, Tamaulipas, Mexico. Took 4 ♂'s of this species, 2 in mouse traps and two in 'live' traps. Habitat- flat country, fairly thick growth of large mesquite and other brush, some cactus. Soil fine, little sandy; grey-brown in color. April 10 1 mi. SE Reynosa, Tamaulipas. Caught 2 ♂'s of this species on sandy soil covered with medium growth of low brush. April 12 Charco Escandido, 20± mi. S Reynosa, Tamaulipas. Took 5♂ and 3♀ of this species. Traps were set along a brush fence near a ploughed field. These mice were abundant along this fence where the mesquite was not thick. Away from the fields I caught practically none at all. April 14 36 mi. ESE Monterrey, Nuevo Leon. Took 3♂ of this species in both live and snap traps. Habitat is