THE TTTIItTKKN-LINKI) (JliOI'NI) SCiriinii:!., 



475 



kind. The animals have also been known to rob the nests of birds. 

 On the whole, however, they do little damage, as most of their food 

 consists of wild seeds and fruits. They are fond of th(i seeds of the 

 giant ragweed or horseweed, and doubtless do some good by de- 

 stroying weed seeds. They also eat some insects, though not enough 

 to be of much use in that way. 



Genus Citellus Oken. 



Citellus Oken., Lehrbuch der Zoologie, Vol. II, p. 842, 1816. 



Allen, Bull. Amer. Mus. Nat. Hist., Vol. 16, p. 875, 1902. 

 Spermophilus Cuvier, Dents des mammiferes, p. 160, 1825. 



Baird, Mam. N. Amer., p. 304. 



Dental Formula.— 1, f:^; C, ~; Pm, flf; M, |e|=22. 



Generic characters. — Size about that of the chipmunks {Tarnias) 

 but form generally more slender ; tail often scantily haired, slender 

 and rounded; cheek pouches present as in Tamias; ears usually 

 short and round; color of the different species various, but never 

 with dark and pale stripes alternating on a chestnut-colored back 

 as in the preceding genus ; upper jaw with five cheek teeth on each 

 side. 



The genus Citellus (usually called Spermophilus) as formerly 

 understood contained a great number of species and had a range in- 

 cluding most of the north temperate zone. Recently this genus 

 has been divided into several genera, but there is lack of agreement 

 as to what species should be included in each. As now understood, 

 the genus still includes a number of species in America, Asia and 

 Europe. 



Two species only are found east of the Mississippi River, and 

 one of these does not extend farther east than north-central Indi- 

 ana, while the other is found as far east as Ohio. They may be 

 distinguished as follows: 



Whitish stripes and rows of dots on the back, in a ground color 

 of brown ; length not over 12 inches. tridecemlineatus. 



Back without nny stripes; length about 15 inches. franklinii 



CITELLUS TRIDECEMLINEATUS (Mitchill). 



STRIPED SPERMOPHILE; THIRTEEN-LINED GROUND SQUIRREL. 

 Also known^as the Striped Gopher. 



Sciurus tridecemlineatus IMitchill, IMedical Repository, New Ser., 



Vol. VI, p. 248, 1821. 

 Spermophilus tridecemlineatus Audubon and Bachman, Quad. 



N. Am., Vol. I, p. 294, 1849. Evermann and Butler, P'roc. Ind. 



