404 EXTINCT MAMMALIA OF NORTH AMERICA. 



Eemains, associated with those of Platygonus, found in the crevices of the lead- 

 bearing rocks near Galena, Illinois. Also in the post-pliocene deposit of Ashley 

 River, near Charleston, South Carolina. 



PALyEOLAGUS. 



Palseolagus Haydeni. 



See page 331, PI. XXVI, Figs. 14-20. 

 Leidy : Proc. Ac. Nat. Sc. 1856, 89 ; 1857, 89. 



From Bear Creek, a tributary of the Sheyenne River, and from the Mauvaises 



Terres of White River, Dakota. Miocene. 



SGIURID^. 



SCIURUS. 



Soinms panolins. 



Cope: Proc. Ac. Nat. Sc. 1869, 3. 



Remains found in a limestone breccia, in association with those of Megalonyx, etc., 

 in Wythe County, Virginia. Quaternary. 



TAMIAS. 



Tamias leexridens. 



Cope : Proc. Ac. Nat. Sc. 1869, 3. 



Remains found in association with the preceding. 



ARCTOMYS. 



Arctom s monax. 



Lei.ly : Traus. Am. Phil. Soc. 1857, XI, 18 ; Hall and Whitney's Rep. Geol. Surv. Wise, and 



Whitney's do. Up. ISIissis. Lead Region, 1862, 424. 

 Teeth found in association with remains of Platygonus in crevices of the lead-bear- 

 ing rocks near Galena, Illinois. Quaternary and recent. 



?Arctomys . 



Stereodecies tortm, Cope : Proc. Ac. Nat. Sc. 1869, 3. 



Based on an incisor tooth, from a bone breccia, from Wythe County, Virginia. 

 The characters upon which both species and genus are founded appear to me abnor- 

 mal. The distortion and unusual solidity indicated by Prof. Cope are probably due 

 to growth unopposed by the corresponding tooth of the other jaw, which had been 

 lost. Such a condition is not unfrequently observed in the Ardomys monax, etc. 



