LAG0MYIM3— LAGOMYS— GEOGRAPHICAL DISTRIBUTION. 409 



Length about 7.00, ranging in adult specimens from 6.50 to nearly 8.00. 

 Ears broad, large, and rounded. Hind foot generally about 1.15 to 1.25 in 

 adults; fore foot about 0.80. The black naked pads at the base of the toes 

 are very prominent. 



The skull ranges in length from about 1.70 to 1.88 ; breadth, 0.82 to 

 0.92; interorbital breadth, 0.21 to 0.25; average length of the nasals about 

 62, narrowing posteriorly from about 0.25 to 0.18. Lower jaw, length, 

 1.07 to 1.25 ; height 0.57 to 0.70. The series of skulls show a considerable 

 range of variation in size in adult specimens. The bones of the skull are 

 thin and papery, and often the parietal suture remains unclosed in fully 

 adult skulls, and the cranial elements of the skull are never to any great 

 extent ankylosed. The nasal bones, however, finally become firmly united. 



The specimens on which the present article is based were all taken on 

 the Snowy range, in Park County, Colorado, and all but two at one locality. 

 The measurements of the animal were all taken in the field by myself, from 

 fresh specimens. 



GEOGRAPHICAL DISTRIBUTION. 



The North American Pika inhabits the summits of the Rocky Mount- 

 ains from Colorado far northward into British America. It is also found 

 near the summit of the Wahsatch range in Utah, the Sierra Nevada in 

 California, and the Cascade Mountains in Oregon. I found it very abundant 

 near the limit of trees in the vicinity of Montgomery, Park County, Colorado,* 

 and Lieut. "VV. L. Carpenter has collected it at other neighboring points of the 

 Snowy Range. Dr. J. G Cooper found it near the limit of perpetual snow in 

 the Sierra Nevada,! where he reports it as quite common over a limited 

 district; while Professor Gabb met with it as far south as the northern 

 boundary of Lower California (lat. 32°), at an altitude of about 10,000 feet. J 

 Mr. J. K. Lord met with it (his " Lagomys mini?nits , '§) near the summits of 

 the Cascade Mountains at an altitude of about 7,000 feet above sea-level, 

 and also at Chilokweyuk Lake, on the western slope of the Cascades || Dr. 



* Bull. Essex Institute, vol. vi, pp. 56, 66. 



tProc. Cal. Acad. Nat. Sci. vol. iii, p. 69 ; ib., 1868, p. 6. 



t Proc. Acad. Nat. Sci. Philad., 1868,2. 



§ The characters Mr. Lord gives for his " Lagomys minimus " do not indicate auy specific difference 

 while the habits he attributes to it are exactly those of the L. princess as recorded by a number of 

 independent observers. He recognized L. princeps as occurring near the same locality; but, because he 

 saw no evidence of L. princeps carrying leaves and grass into lis warrens, he regarded the animals seen at 

 the two neighboring localities as distiuct species. His " Fiber osoyoosensis ", described in the same paper, 

 rests on similar mistaken assumptions. 



|| Proc. Zoiil. Soc. Lond., 186;!, pp. 96, 97. 



