MAMMALS OF THE MEXICAN BOtJNDARY. 



511 



foot, 4:5; head, 50. Skull, 45 by 26. Mammse, 4 pairs. Pattern 

 striped, as in Tainkis and Eutamias, but without a median dorsal 

 stripe. A broad white stripe extends along the side, from shoulder 

 to thigh, narrowing posteriorly; and this is bordered above and below 

 by black, the lower black stripe being the most pronounced. The 

 rest of the upper side of the body is grizzled vinaceous cinnamon, 

 intimately mixed with black anteriorly, and more vinaceous posteriorly. 

 Crown, cheeks, sides of neck, shoulders, and outer aspect of limbs 

 vinaceous cinnamon. Side of head with a whitish line extending from 

 nose to ear, involving the eye; .underside of head, white. Sides of 

 '^ody j'ellowish, paler and grayer next to the black longitudinal stripes. 

 Under surface of body, soiled yellowish white. Tail grajnsh yellow, 

 sometimes vinaceous, the lateral hairs thrice ringed with black. Ears 

 coated with short, ferruginous hairs, both surfaces, white at base 

 anteriorly. 



Skull. — The skull (fig. 49) of Callospermophilus lateralis diflers 

 widely from those of Am/inospermophilus leucii/r^us and A. Jiarrisii. In 

 fact, the lateralis group stands out distinctly from both the genera 

 Tainias and Eutamias. and from Ammmpermophilus, and merits sepa- 

 ration as a section of the genus Gitellus. (Since the above was written 

 it has been named Callospermophilus by Merriam, and regarded as a 

 full genus.) 



The skull closely resembles that of typical Gitellus {Mm citellus Lin- 

 naeus). The brain case is less flattened superiorly than in Ammosper- 

 m,ophilus., with more prominent and higher parietal crests. The audital 

 bullae are smaller, and the width of the basi-sphenoid, basi-occipital, 

 and interpterygoid notch relatively much greater. The incisive fora- 

 men is longer. 



Cranial measurements of 4aduU females of Callospermophilus lateralis from near 

 Flagstaff, Arizona. 



Ee7na/r]i'S.—Th& larger ears, and the addition of black longitudinal 

 stripes, are in the direction of the genera Tamias and Eutamias; but 



