VOL. XVIII, PP. 163-166 JUNE 29, 1905 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW CHIPMUNKS FROM COLORADO AND ARIZONA. 

 BY C. HART MERRIAM. 



Both of the chipmunks here described are of unusual interest. 

 One inhabits the pinyon and juniper belt in the desert region of 

 northeastern Arizona and southeastern Utah, and is one of the 

 handsomest members of the genus ; the other is the common 

 small chipmunk of the high mountains of Colorado ; it has been 

 previously confused with quadrivittatus of Say, which proves to 

 be a much larger species. The specimen on which Say's species 

 was based was collected by Long's Expedition to the Rocky 

 Mountains on July 17 or \8, 1830, on the Arkansas River. The 

 party, which included the naturalist Thomas Say, was encamped 

 from the evening of July 16 to the morning of July 19, at a 

 locality described as about thirty miles below " the place where 

 the river leaves the mountains," which would be about 26 miles 

 below the present Canyon City. Referring to this camp, Say 

 states, "Among the animals taken here, was the four-lined 

 squirrel ($. ^-vittatus} a very small and handsome species." 

 This fixes the type locality with a definiteness not open to 

 question . 



Recent field work in eastern Colorado shows that two species 

 of chipmunk occur in the region, one inhabiting the Boreal zone 

 in the high mountains, the other the Transition and Upper 

 Sonoran foot hills, extending out toward the plain as far as the 

 land is covered with a scattered growth of junipers. The 



28-PROC. BIOL. Soc. WASH., VOL. XVIII, 1906. (163) 



