PEROGNATHUS. 355 
Measurements. Total length, 117; tail vertebrae, 71; hind foot, 
17; ear, 4. Skull: length of Hensel, 14.6; occipito-nasal length, 21; 
greatest mastoid breadth, 12; length of interparietal, 2.6; greatest 
width of interparietal, 2.9. 
a,—mexicanus (Perognathus), Merr., Proc. Acad. Nat. Scien. Phil., 
1894, p. 265. 
Mexican Pocket Mouse. 
Type locality.. Tlalpam, Federal District, Mexico. 
Geogr. Distr. States of Zacatecas and San Luis Potosi to the 
State of Jalisco on the west and State of Hidalgo on the east, and 
south to the State of Mexico. 
-Genl. Char. Similar to P. flavus, but darker and larger. 
Color. Above buff, mixed with black; spot behind ear, and the 
lateral line ochraceous; under parts white; tail dusky above, paler 
beneath. 
Measurements. Total length, 115.7; tail, 53.7; hind foot, 17.4. 
panamintinus brevinasus (Perognathus), Osgood, N. Am. Faun., 
No. 18, 1900, p. 30. Elliot, Syn. N. Am. Mamm., 1901, p. 246. 
SHORT-NOSED Pocket MOUSE. 
Type locality. San Bernardino, San Bernardino County, Cali- 
fornia. 
Geogr. Distr. Lower California north to southern California. 
Genl. Char. Similar to P. panamintinus, but darker. Skull 
smaller; interparietal smaller, nasals shorter; lower premolar larger 
than last molar. 
Color. Above pinkish buff, lined with black; lateral line pinkish 
buff; ears dusky, orbital ring buffy; tail buffy white, faintly dusky 
above. 
Measurements. Total length, 124; tail vertebre, 66; hind foot, 
17.4. Skull: length’ of Hensel, 14.9; occipito-nasal length, 21.4; 
mastoid breadth, 11.9; length of interparietal, 2.5; greatest width 
of interparietal, 3.5; interorbital constriction, 5.2; length of nasals, 
Ong: 
361. pacificus (Perognathus), Mearns, Bull. Am. Mus. Nat. Hist., 
n50o8..p..290, Elltot, Syn: N. Am: Mamm., tger, p. 246. 
PaciFic Pocket Mouse. 
Type locality. Mouth of Tijuana River, Mexican boundary 
Monument, No. 258, shore of Pacific Ocean, San Diego County, 
California. 
Geogr. Distr. Edge of Pacific Ocean, on a flat at mouth of 
Tijuana River, and probably into Lower California, Mexico. 
