RODENTIA—SCIURINAE—CYNOMYS LUDOVICIANUS. 331 
CYNOMYS LUDOVICIANUS. 
Missouri Prairie Dog. 
Arctomys ludovicianus, Orv, Guthrie’s Geog. 2d Am. Ed. II, 1815, 292, 302. 
Say, in Long’s Exped. R. Mts. I, 1823, 451. 
Haruan, F. Am. 1825, 160. 
Gopman, Am. N. H. II, 114. 
Grirr. Cuv. IIIf, 1827, 198. (Plate taken fiom Lewis and Clark’s specimen in Peale’s 
Museum.)—Is. V, 1827, 247. 
Prince Max. Reise in das innere Nord-Amerika, I, 1839, 365. 
Wacener, Suppl. Schreber, III, 1843, 261. 
Spermophilus ludovicianus, ‘* Lesson, Manual, 244, 658.” 
F. Cuvier, Suppl. Buffon, I, Mam. 1831, 316 
Aup. & Bacu. N. Am. Quad. II. 1851, 319 ; pl. xcix. 
Kennicorr, Rep. U.S. Pat. Off. Agricultural for 1856, (1857,) 81; pl. ix. 
Cynomys soctalis, Rarinesque, Am. Month. Mag. IJ, Nov. 1817, 45. 
Brants, Muizen, 1827, 171, (from Raf.) 
Lesson, Nouv. Tab. R, An. 1842, 115. 
Cynomys grisea, Rarinesque, Am. Month. Mag. II, Nov. 1817, 45. 
Brants, Muizen, 1827, 172, (from Raf.) 
Arctomys griseus, FiscHer, Synopsis, 1829, 345. 
*< Arctomys missouriensis, WARDEN, Desc. U. S. V. 1820, 627.” 
Arctomys latrans, Harian, F. Am. 1825, 306. 
Barking Squirrel, Lewis and Crark, II, 1815, 175. 
Size of fox squirrel, Sc. vulpinus, but heavier ; ears very short, not projecting above fur. Tail short, with the hairs, about 
one third the length of body. Claws long, very stout; the thumb of fore feet armed with a long claw instead of a flat nail. 
Soles with a patch of hair. Color above reddish brown or cinnamon, with the tips of the hairs lighter and with scattered black 
hairs interspersed ; beneath brownish white or yellow. In winter of a more grayish cast above. Hairs on the upper part lead 
color at base, then pale cinnamon white to cinnamon, Tail like the back, its tip black, with the hairs light colored at base. 
Length about 12 inches ; tail, with hairs, 4; hind foot about 2.25 inches. 
This species, in external form and terrestrial habits, approaches the true marmots, as it does 
likewise in its internal structure. The cheek pouches are small and not easily detected, even 
in a fresh specimen. The body is stout and clumsy, a woodchuck (Arctomys monax) in 
miniature. The ears are very short, with scarcely any rim whatever, and. this not projecting 
beyond the short fur. The septum of the nose is naked; the hairs elsewhere come almost into 
the nostrils. The fore feet are large, and the thumb is armed with a strong claw as long and 
stout as that on the fifth or exterior finger. The third finger is largest; second and fourth 
nearly equal, and the claw of the fifth does not reach to the base of the claw of the fourth. The 
third toe is longest ; the fourth but little shorter ; the second reaches to the middle of the claw 
of the third ; the fifth not to the base of that of the fourth; nor the first to that of the fifth. 
The palms are naked ; the soles nearly so, with the exception of a central patch under the base 
of the metatarsus. The tail is short, usually about one-third the body, sometimes not more 
than a fourth ; it is covered nearly uniformly everywhere (with but a moderate degree of flat- 
tening) with stiff hairs. 
The prevailing colors of this animal in summer are reddish brown, almost a light chestnut 
or cinnamon, turning gradually into brownish yellow on the sides, and lighter tint of the same 
beneath, without any distinct line of demarcation anywhere. A closer examination above, 
however, shows that the reddish brown is tipped with a paler tint of the same or of brownish 
yellow, and that there are numerous black hairs interspersed. The hairs individually are very 
