MAMMALS OF PENNSYLVANIA AND NEW JERSEY. 245 



Microtus dideltus (Cope). Fossil Pine Vole. 



1871. Arvicola didelta Cope, Proc. Amer. Philos. Soc., vol. xii, p. 89, 



fig- IS- 



1871. Arvicola sigmodus Cope, Proc. Amer. Philos. Soc., vol. xii, p. 90, 

 fig. 17. 



1899. Microtiis dideltus Cope, Journ. Acad. Nat. Sci., Phila. (2), vol. xi, 

 pt. ii, p. 207. 



Type locality, Port Kennedy, 1. c. Type in Amer. Mus. Nat. Hist, N. Y. ? 



Pleistocene. Port Kennedy, Montgomery Co., Penna. Mandibular rami 

 and superior dentition. This vole is so closely related to the existing M. 

 pinetorum as to suggest their identity. 



Microtus involutus (Cope). Involute Fossil Vole. 



1871. Arvicola involuta Cope, Proc. Amer. Philos. Soc., xii, p. 89, fig. 16. 

 1896. M.\icrotus\ involutus Cope, Proc. Acad. Nat. Sci., Phila., p. 382. 

 Type locality. Port Kennedy, 1. c. Type in Amer. Mus. N. Hist., N. York. ? 

 Pleistocene. Port Kennedy, Montgomery County, Penn. Mandibular 

 ramus with full series of teeth. 



Fiber zibethicus (Linnaeus). Eastern Muskrat. 



1869. Fiber zibethicus Leidy, Extinct Mamm. N. Amer, p. 406 ; Ann. Rep. 

 Penn. Geol. Surv., 1887, pp. 5 and 19, 1889. 



Pleistocene. Hartman's Cave, near Stroudsburg, Monroe Co., Penna. 

 Various bones and teeth. Durham Cave, near Riegelsville, Bucks Co., Penna. 

 "Associated with Mastodon remains in New Jersey." See list (antea) of 

 references to recent muskrat. 



Family ZAPODID^: ; American Jumping Mice. 

 1873. Genus Zapus Coues, Bui. U. S. Geolog. Surv., No. 5, ser. 2, p. 253. 



Zapus hudsonius (Zimmermann). Eastern Meadow Zapus. 



1871. Jaculus ? hudsonius Cope, Proc. Amer. Philos. Soc., xii, p. 86. 

 Pleistocene. Port Kennedy, Montgomery Co., Penna. One mandibular 

 ramus. See list (anfea) for references to recent Zapus. 



Family CASTOROIDID^E ; Giant Beavers. 

 1838. Genus Castoroides Foster, Second Report Geol. Surv. Ohio, p. 81. 



Castoroides ohioensis Foster. Great Fossil Beaver. 

 1838. Castoroides ohioensis Foster, Second Ann. Rep. Geol. Surv. Ohio, 

 p. 81. 



