64 Cincinnati Society of Natural History. 



NORTH AMERICAN SCIURID^ OR SQUIRRELS. 

 By Chas. Dury. 



(Read September 3, 1889.) 



The Sciuridce or squirrels of America north of Mexico, present 

 one of the most interesting and variable families of our mammalian 

 fauna. This variation of color and^ize in individuals of the same 

 species, from the northern to the southern boundaries of the coun- 

 try, is extreme, and it is not surprising that Audubon and Bach man, 

 in their North American Quadrupeds, published in 1 849— '5 1 and 

 '54, should have enumerated 38 species in this family, as many 

 of them were described from very inadequate series of specimens to 

 illustrate intergrading variation and geographical range. In 1857 

 Prof. B drd, with a much larger series of specimens, enumerates 38 

 species(i). Twenty years later Prof. J. A. Allen issued his Mono- 

 graph of the American Sciuridce{2). In this excellent work, which 

 leaves little to be desired, Mr. Allen reduces the 38 species to 25, 

 and the 12 species of Sciuri proper of Baird to five, with seven 

 named varieties. In the preparation of this memoir, Mr. Allen 

 examined over two thousand specimens, and his remarks on com- 

 parisons of anatomical and color peculiarities are very instructive 

 and interesting. 



Dr. Coues says, in his chapter on rodents, Standard Natural 

 History, Vol. V.: "No animals are more inconstant than the 

 squirrels in coloration. Color is nothing in a squirrel. Ignorance 

 of the laws of color variation has caused nominal species without 

 number to be introduced." In this connection I would urge upon 

 this Society the importance of securing a large series, covering as 

 wide a range as possible in this family. 



The squirrels are the embodiment of grace and symmetry. Their 

 movements are executed with the rapidity of lightning and the 

 greatest precision. The Gray Squirrel (S. Caiolinensis leucotis) is one 

 of the most active of animals, when alarmed rushing through the 

 tree-tops, making headlong leaps from bough to bough. It can get 

 over the ground as fast as a man can run along it. The only 

 species of squirrels I have ever met with in this locality were the 



(I). Pacific R. R. Survey, Vol. VITL, p. 240. 

 (2). Hayden Survey. Vol. XI., p. 633. 



