12 
ZOOLOGY. 
Sh Ch. —Size of the eat squirrel, S- cinereus. Ears large, prominent Tail more than two-thirds as long as the body. Above, 
mixed black, yellowish brown, and brown in indistinct mottlings; beneath, pale yellowish brown. Sides of head and neck, hoary 
yellowish, more or less lined with black, a more distinct stripe of the same, from behind the ears on each side, extending above 
the shoulders to the middle of the body. Ears black on their inner face. Dorsal space between the stripes scarcely darker 
than the rest of the back. Length, 9 to 11 inches; tail, with hairs, 7 to 9. Hind feet, 2 to 2.30 inches. 
These animals are very abundant near the Cocomongo Rancho, and indeed throughout the 
valley of the San Gabriel river. They were always found living in communities, and in general 
habits resembled the prairie dog, Spermophilus ludovicianus. Their size is about that of the 
common gray squirrel, or a little larger. Their color is usually a rusty gray ; I have, how¬ 
ever, seen some almost entirely black. The burrowing owl, Athene hypugaea, which is the 
constant companion of the prairie dog, is also found among these animals in considerable 
numbers. (No. 157. Lost on the Isthmus.) 
?SPERMOPHILUS HARRISII, Aud. & Bach.— Harris’ Squirrel. 
Spermophilus harrisii, Aud. & Bach. N. Am. Quad, III, 1854, 267; pi. cliv, fig. 1. 
Baird, Gen Rep. Mammals, 1857, 313. 
Size rather less than that of Tamias striatus. Tail vertebrae about half the length of the body. Ears short, pointed. Soles 
hairy. Above, finely grizzled grayish, or whitish brown and black ; under parts, and a stripe on each side, (without any black 
or dusky border,) whitish. Tail with one black and one light line, within the marginal whitish, black in the centre; uniform 
whitish beneath. Length, 5 inches; tail, with hairs, about 3. Hind foot, 1.45. 
This beautiful and rare spermophile is found in considerable numbers at Cold Spring, near 
the summit of the Sierra Madre. In this vicinity there were huge piles of scoriaceous rock in 
which it lived. It was not very sliy, but a specimen was procured with difficulty, owing to the 
fact that it was almost impossible to kill tlie animal before it could escape into the rocks, and 
avoid blowing it to pieces. Its food, in this locality, consisted of pihones and acorns. We 
again observed this animal near Camp 139, between the Colorado and Mohave rivers. Here we 
found it on the bill-sides in the most rocky and inaccessible spots, and exceedingly shy. (No. 
6. Lost on the Isthmus.) 
SPERMOPHILUS, ? 
This animal was found among the rocks on the bill-sides in the immediate vicinity of Bill 
Williams’ Fork, Camp 117. It was very active, and ran with great rapidity. It was some- 
Avhat larger than the S. tridecem lineatus; its color a uniform rusty gray, its belly somewhat 
lighter. Its hair was rather coarse ; its tail short and bushy. Two specimens were obtained, 
(119,) but lost on the Isthmus, which prevents its identification. It seemed to resemble some¬ 
what the S. townsendii. 
CYNOMYS LUDOVICIANUS, Rich .—Missouri Prairie Dog. 
Arctomys ludovicianus, Ord, Guthrie’s Geog. 2d Am. ed. II, 1815, 292, 302. 
Spermophilus ludovicianus, “Lesson, Manual, 214, 658.” 
F Cuvier, Suppl. Buffnn, I, Mam. 1831, 316. 
Aud. & Bach. N. Am. Quad. II, 1851, 319; pi. xeix. 
Oynomys ludovicianus, Baird, Gen. Rep. Mammals, 1657, 331. 
Size of fox squirrel, S. 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 the 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 
