As if sciurus Hudsonius didn't know what he were about!
"Birds in the Bush"
Bradford Torrey
sciurus carolinensis carolinensis Gmelin.
"Distribution of Some Nebraskan Mammals"
J. Knox Jones
He then goes on to show that the tail is bushy in seventeen species, partially distichous in one, and wholly so in ten, and concludes by saying: "I am therefore disposed to regard the flying squirrels generally as constituting a well-defined generic group, the parallel of the genus sciurus, which consists of an extensive series of specific forms distinguished by a remarkable uniformity of structure, both in their skulls and skeletons, and in the formations of their soft parts."
"Natural History of the Mammalia of India and Ceylon"
Robert A. Sterndale