Interesting, Faldage.

http://cancerweb.ncl.ac.uk/cgi-bin/omd?assapanic

This site, among others I checked, claims that the assapanic is American--and that it is Pteromys.

Did any of the Old World flying squirrels become naturalized here?

Ah! Edit: There are Pteromys and Pteromys, both Old and New World Pteromys, but ours has the genus and species I noted above when searching for "American flying squirrel."

What was Rocky?