PEROGNATHUS. 3.'>9 



Geogr. Distr. Northwestern Mexico west of the Sierra Madre, 

 north into south central Arizona. 



Genl. Char. Similar to P. penicillatus, but smaller; no spines on 

 rump; pelage harsh; skull short. 



Color. Above and on sides vinaceous buff, lined with black; 

 lateral stripe indistinct; under parts white; tail above dusky, beneath 

 white; ears like back. 



Measurements. Total length, 172; tail vertebrae, 90; pencil, 10; 

 hind foot, 23; ear, 7.5. Skull: occipito-nasal length, 26; Hensel, 

 18.4; greatest mastoid breadth, 13; length of interparietal, 6.7; 

 greatest width of interparietal, 6.2; length of nasals, 9.4. 



peniciUatus eremicus (Perognathus) , Mearns, Bull. Amer. Mus. Nat. 

 Hist., 1898, p. 300. Elliot, Syn. N. Am. Mamm., 1901, p. 253. 

 EASTERN DESERT POCKET MOUSE. 



Type locality. Fort Hancock, El Paso County, Texas. 



Geogr. Distr. North central Mexico east of the Sierra Madre to 

 La Ventura, State of Coahuila, and north into western Texas. 



(icnl. Char. Small; colors pale; skull rather heavy. 



Color. Above whitish drab, tinged with fawn and lined with 

 dusky; lateral stripe faint; feet and lower parts white; tail above 

 and tip pale brown, beneath white. 



Measurements. Average total length of six, 163; tail vertebrae, 

 83; hind foot, 22.1; ear from base, 9.1. Skull: Hensel, 17.5; greatest 

 mastoid breadth, 12.6; length of interparietal, 3; greatest width of 

 interparietal, 7; interorbital constriction, 6.4; length of nasals, 9.3. 



362. pernix (Perognathus), Allen, Bull. Amer. Mus. Nat. Hist., 1898, 



p. 149- 

 SINALOA POCKET MOUSE. 



Type locality. Rosario, State of Sinaloa, Mexico. 



Geogr. Distr. States of Sinaloa and Jalisco, Mexico. 



Genl. Char. Size small; colors dark; no spines; tail long. 



Color. Upper parts hair brown; lateral line pinkish ochraceous 

 buff; under parts whitish; tail brownish above, whitish beneath; 

 ears dusky with white dot on inferior margins. 



Measurements. Total length, 175; tail vertebrae, 97; hind foot, 

 22.3. Skull: occipito-nasal length, 24.4; Hensel, 17.4; greatest mas- 

 toid breadth, 12.2; length of interparietal, 3.3; greatest width of 

 interparietal, 7.2; interorbital constriction, 5.4; length of nasals, 8.6. 



a. rostratus (Perognathus), Osgood, N. Am. Faun., No. 18, 1900, p. 51. 

 BROAD-NOSED POCKET MOUSE. 



Type locality. Camoa, Rio Mayo, State of Sonora, Mexico. 



