No. 2391. DESCRIPTIONS OF PLEISTOCENE VERTEBRATA—HAY. 611 



BISON, species indeterminable. 



A species of Bison is indicated by one first phalange. Its proximal 

 end is broken off. It is possible that it belongs to the preceding 

 species. The catalogue number is 10318. 



MARMOTA ARRODENS, new species. 



Plate 117, figs. 3-5, 7, 9; plate 118, figs. 1, 3, 4. 



Type specimen. — Lower jaw, No. 2656, U. S. N. M. 



Type locality. — Chelan County, Washington. 



Type formation. — Pleistocene. 



Diagnosis. — Size large. Lower incisors in adults equaling in 

 breadth about two-fifths of the length of the row of molar teeth; its 

 outer face, behind the enamel, furnished with a prominent ridge. 



In the collection here considered there is a considerable number of 

 teeth and bones of woodchucks. There appear to be present two 

 species. One of these, represented by a lower jaw, probably also by 

 other bones, was an unusually large marmot. As type of this sup- 

 posed species are taken the right and left rami of the lower jaw, which 

 bear the catalogue number 2656 of the United States National 

 Musuem. Neither of these rami is complete, the better preserved one 

 lacking the coronoid, condylar, and angular processes (pi. 117, figs. 

 3, 4). 



Inasmuch as the locality which furnished these bones lies within 

 the area occupied by Marmota flaviventer and close to that occupied 

 by subspecies of M. caligata, it is fair to make comparisons with the 

 two species mentioned. 



Measurements of teeth and lower jaws of species of Marmota. 



Distance from incisivo border to border between the condylar and angular 



processes 



Length of row of molars 



Height of jaw on inside at front of last molar 



Height of jaw between symphysis and first molar 



Width of incisors at the bone 



Thickness of incisor at bone 



M. cali- 

 gata. 



64 

 22 

 15.5 

 12.5 



7 



4 



Besides the ridges and grooves of various widths usually found on 

 the enamel of the incisors of the species of Marmota, there is in M. 

 arrodens, about halfway between the hinder edge of the enamel and 

 the hinder border of the tooth, a prominent ridge. In front of it is a 

 broad groove; behind it a narrower one. On the enamel there are 

 distinct remains of the original pale orange color. 



There are various limb bones which may or may not belong with 

 the jaw just described. They may, indeed, belong to the same indi- 

 vidual. In the jaw the molar teeth are all worn down smooth, while 



