Vol. XXV, pp. 57-58 April 13, 1912 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW AMERICAN PIKAS. 



BY X. HOLLISTER. 

 [Published bj permission of the Secretary of the Smithsonian Institution.] 



Specimens of the two new species of Ochotona herewith de- 

 scribed have been in the collection of the United States National 

 Museum for many years. The recent acquisition of relevant 

 material and the identification of all the American specimens 

 in the group, have shown the necessity of recognizing addi- 

 tional forms. 



Ochotona levis sp. nov. 



Type from Chief .Mountain Lake, Montana. Adult 9 , skin and skull. 

 I'. S. National Museum, No. UUh Collected August 24, 1S74. Dr. 

 Elliott Coues. Orig. No. 4593. 



General characters. — Size small,; skull decidedly smaller than that of 

 Ochotona princeps, 0. cuppes, or 0. saxatilis. Coloration most like 0. 

 princeps; but fresh coat, especially on cheeks and sides, lighter, with 

 more yellowish-burl". 



Color. — Head and upperparts of body light huffy brown, paler on nape; 

 cheeks and sides of neck brighter rufous; area behind ears light buff. 

 Color of back blending through lighter brownish-buff of sides to cream 

 buff of underparts; breast often washed with rufous. Hands, above and 

 below, cream buff; feet buff above, with soles somewhat dusky. 



Skull smaller than in any of the neighboring forms. 



Measurements of type. — Head and body, 168 millimeters; tail vertebrae, 

 10. Skull of type compared with skull of adult female Ochotona princeps 

 from head of Smoky River', Alberta, the latter in parentheses: Greatest 

 length, 41.7 (44.2); condylobasal length, 39 (41.2); zygomatic breadth, 

 20.5 (21.6); nasals, 13.6 (14); alveolar length of upper tooth row, 8 

 (8.5). 



Remarks. — Eight specimens of Ochotona levis are in the collection ; rive 

 from the type locality, one from the Belt Mountains, Montana, and two 

 from the Bitter Root Mountains, Idaho. The species is at once distin- 



10— Proc. Biol. Soc. Wash., Vol. XXV, 1912. (57) 



