300 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Ammospt rmophilus harrisii (p. 303), but with the nasal hones narrower 

 posteriorly. 



Remarks. — April and May specimens, in the Coast Range Moun- 

 tains, California, were mostly in winter pelage, but molting more or 

 less into the summer pelage. The large series of young specimens, 

 of various ages, collected at this time is instructive as showing the 

 changes and their sequence before the adult pelage is acquired. Ten 

 very young specimens (size of Blarina brevicauda), from one burrow, 

 are rather thinly clad in a dress that resembles their parents', though 

 with the markings intensified. The crown, rump, and outer surface 

 of limbs are vinaceous cinnamon; upper surface of tail black with 

 white-tipped hairs along - sides and at extremity; back gray anteriorly, 

 dusky, grizzled, vinaceous posteriorly; side stripes pure white; feet 

 rusty white; under surfaces yellowish white, except the tail, which is 

 pure white. Before the animal is half grown this coat fades and 

 acquires a dull olivaceous tinge. Molting begins when the animal is 

 half grown, commencing posteriorly and proceeding much as in the 

 autumnal molt of adults. 



Specimens from the eastern base of the Coast Range Mountains are 

 paler than those from the notches at or across the summit of the divide. 



This beautiful species had long been in collections, but overlooked 

 and confounded with Ammosperm op hilus harrisii until described, in 

 L889, by Doctor Merriam, who subsequently" made it the type of 

 his subgenus AmmospermophUus, which has since been recognized as 

 a genus. 



Habits and /<><■/// distribution. — Gen. George Crook called my atten- 

 tion to the difference between this species and Ammospermophilus har- 

 risii November 10, 1884, when we rode through 27 miles of the lower 

 portion of Cataract Creek, in northern Arizona. We found it to be 

 numerous in the Cataract Creek Canyon, about the Havasupai Indian 

 village, and on November 13, 1884, saw many of them in the side 

 caivyon through which the Hualapai Indian trail led to the westward. 

 They scurried from bush to bush, with tail erected at right angles with 

 the body, thus showing the white pattern. My first specimen was shot 

 on the trail leading to Vitz's crossing on the Colorado, November 16. 

 Three antelope ground-squirrels had one burrow at the side of a small 

 canyon and another at the top of the canyon, under a large stone, 

 beneath which 1 found a large heap of yucca fruits and cones of pifion 

 pine. 



On the Mexican Boundary this species was not met with until the 

 easl base of the Coast Range Mountains was reached, when it appeared 

 on entering the wagon pass through these mountains at the lowest 

 water. At Mountain and Jacumba springs it was very abundant. It 



aProc. Biol. Sue. Wash., VII, p. 27, April 13, 1892. 



