PEROGNATHUS. 363 
greatest width of rostrum, 5; palatal length, 13; length of tooth row, 
alveolar border, 4; length of mandible, tip of angle to alveolus of 
incisor, 14.2. 
367. margaritz (Perognathus), Merr., Proc. Cal. Acad. Scien., 2d 
Ser., 1894, Pp. 459. 
MArGARITA Pocket Mouse. 
Type locality. Santa Margarita Island, Lower California, Mexico. 
Geogr. Distr. Type locality only. 
Genl. Char. Size medium; tail longer than head and body. 
Skull: mastoids small; occiput not projecting posteriorly. 
Color. Upper parts pale fawn mixed with black; lateral line 
indistinct; subauricular spot small; under parts and feet whitish; 
tail above dusky, beneath whitish. 
Measurements. Total length, 180; tail vertebre, 102; hind foot, 
22.5. Skull: occipito-nasal length, 25.9; Hensel, 18; greatest mas- 
toid breadth, 12; length of interparietal, 12; greatest width of inter- 
parietal, 8; interorbital constriction, 6.5; length of nasals, 10.3. 
368. spinatus (Perognathus), Merr., N. Am. Faun., No. 1, 1880, 
p. 21. Elliot, Syn. N. Am. Mamm., rigor, p. 255. 
Spiny Pocket Mouse. 
Type locality. Twenty-five miles below the Needles, Colorado 
River, San Bernardino County, California. 
Geogr. Distr. Northern Lower California, Mexico, and southern 
California. 
Genl. Char. Size medium; tail longer than head and body, 
crested; antitragal lobe large; soles naked; rump spinous. 
Color. Above drab gray, lined with black; no lateral stripe; 
fore legs, feet, and under parts white; tail above dusky; below white; 
pencil dusky. 
Measurements. Total length, 179; tail vertebre, 104; pencil, 15; 
hind foot, 21; ear from crown, 3.5. Skull: occipito-nasal length, 28; 
Hensel, 19.8; greatest mastoid breadth, 13.1; length of interparietal, 
4; greatest width of interparietal, 8.3; interorbital constriction, 6.5; 
length of nasals, 11.2. 
a.—peninsule (Perognathus), Merr., Proc. Cal. Acad. Scien., 2d 
Ser., 1894, p. 460. 
Cape St. Lucas Pocket Mouse. 
Type locality. San José del Cabo, Lower California, Mexico. 
Geogr. Distr. Cape region of Lower California, Mexico. 
Genl. Char. Similar to P. spinatus, but larger; tail shorter: 
ears large, rounded; skull with comparative differences. 
