Nelson and Goldman — New Mammals from Lower California. 25 



larger, heavier; zygomatic arches more strongly divergent anteriorly; 

 brainease more elongated; palate with posterior median extension 

 thinner; palatopterygoids broader; molar series heavier; incisors more 

 decnrved — not projecting forward l)eyond tip of nasals as in rvsseolus. 



Mensurements of type. — Total length, 255; tail vertebne, 87; hind foot, 

 ;-5(). Skull: basilar length, 38.4; zygomatic breadth, 20.1 ; alveolar length 

 of upper molar series, 8.9. 



Thomomys bottae russeolus snbsp. nov. 



SAN ANGEL I'OrKET (iUl'HER. 



Type from San Angel, 30 miles west of San Ignacio, Lower California, 

 Mexico. No. 139,920, U. S. National Museum, Biological Survey Collec- 

 tion. cJ* young adult. Collected October 15, 1905, l)y E. W. Nelson and 

 E. A. Goldman. Original number 18,355. 



General characters. — Color as in magdalena: , much i)Hler than in either 

 anittv or nigricans; skull smaller, lighter, less angular than in anitiv, with 

 bulhe more fully roimded and basioccipital more constricted. 



Color (rather worn pelage). — Upperparts pale ochracetjus huffy much 

 like maydalenie; underparts dull creamy white, varying to pale buff across 

 belly; feet and tail thinly clotlied with whitish hairs. 



Skull. — Much like tliat of arut:r, but smaller, lighter, less angular; 

 bulla' more rounded; basioccipital narrower; incisors snuiUer; compared 

 with nigricans skull smaller, with shorter rostrum ; bulhe more rounded ; 

 basioccipital more constricted, less triangular or wedge-shaped, sides more 

 nearly parallel. 



Measureuicnts of type. — Total length, 208; tail vertebne, 73; hind foot 

 (dry skin), 29.5. 



Vulpes macrotis devius subsp. nov. 



PENINSTLA DESERT FOX. 



Type from Llano de Yrais, opposite Magdalena Island, Lower Califor- 

 nia, Mexico. No. 147,078, U. S. National Museum, Biological Survey 

 Collection, d" adult. Collected December 13, 1905, by E. W. Nelson 

 and E. A. Goldman. Original number 18,771. 



General characters. — Similar to macrotis but distinguishable by much 

 darker, usually blackish, sides of nose, and sides of under jaws in front 

 (sometimes including entire chin); pelage shorter; tail smaller and slen- 

 derer. 



Color (fresh pelage). — Upperparts silvery gray; forehead and cheeks 

 huffy grayish; outer sides of legs, collar on underside of neck, and poste- 

 rior base of ears deep ochraceous buff, deepest or most intense on hind 

 legs; sides of neck, belly, underside of tail and sides of body along flanks 

 between fore and hind legs varying from deep buff to pale ochraceous buff'; 

 throat, inguinal region and usually median line of belly white; ears,, except 

 at posterior base, huffy l)rown ; feet l>uffy whitish al)Ove ; ochraceous huffy 

 below; lips, sides of muzzle (sometimes chin) and tij) of tail blackish. 



Skull. — About equal in size to that of macrotis but rostrum broader and 



