72 Expedition to the 



stature of dwarfs by the distance, and by contrast with the 

 rude and colossal features of the scene. The surface of the 

 country, extending on both sides from the summit of the pre- 

 cipices, consisted of abrupt conic piles, narrow ridges, and 

 shapeless fragments of naked rocks, more impassable than the 

 valley below. Counselled therefore by necessity, we resum- 

 ed our former course, ascending along the bed of the creek. 



Among other birds, which occurred in this day's march, 

 we noticed the yellow-bellied Jly-catcher, and the obscure 

 wren. 



One of the small striped ground squirrels already noticed, 

 was killed, and an individual belonging to another species* 

 distinguished by the extraordinary coarseness and flattened 

 form of the fur, and by three black lines on each side of the 

 tail. These lines at their tips, are of course, united over the 

 surface of the tail, as in the Barbary squirrel. It nestles 

 in holes and crevices of the rocks, and does not appear to 

 ascend trees voluntarily. 



It inhabits frequently about the naked parts of the sand- 

 stone cliffs, or where are only a few cedar bushes. In the 

 pouch of the specimens killed, we found the buds and leaves 

 of a few small plants common among the rocks. 



Following up the bed of the creek, \Ye ascended by a gra- 

 dual acclivity, to the surface of the stratum of red sand- 

 stone. It is separated by a somewhat distinct boundary from 

 the finer and more compact gray variety which rests upon it. 



* Genus Sciurus. 



S. grammurus. Say. Line-tailed squirrel. Body cinereous, more or less 

 tinged with ferruginous; fur very coarse, much flattened, canaliculate 

 above, plumbeous or blackish at base; then whitish, or ferruginous; tip 

 brownish; above the neck and shoulders the whitish is prevalent; from the 

 middle of the back, the sides, and the exterior surface of the legs, the fer- 

 ruginous colour prevails, the terminal brown of the feet being obsolete; 

 superior and inferior orbits of the eye white; tail moderate whitish; fur 

 triannulate with black, the base and tip of each hair being whitish; be- 

 neath, whitish tinged with ferruginous; thumb tubercle armed; iris burnt 

 umber: pupil black. 



Length to the origin of the tail, 111-2 inches. 

 Of the tail, . . 9 inches. 



