54

former assuming a variety of colors-black, brown, red, blue, and light yellow, -and containing small white particles of carbonate of lime. The darker varieties of clay greatly predominate over the others, and are always observed nearest the surface. The sand is only occasionally seen, and does not attain any considerable thickness. It is for the most part coarse, highly ferruginous, and contains pebbles of metamorphic rocks scattered through it, and is sometimes loosely cemented with ferruginous and calcareous matter.

The surface is often characterized by numerous small ridges, from two to three feet high, familiarly known as "Hog Wallows."

Soil a deep vegetable mould, highly productive; sub-soil generally calcareo-argillaceous, sometimes arenaceous.

Distance traveled, 25 miles.

April 5.-For the first fifteen miles we continued to travel over deposits of the same character as noted yesterday. Afterward the formation became much more arenaceous, consisting chiefly of coarse yellow quartzose sand, with pebbles and small boulders of silicious rocks disseminated through it. Surface gently undulating, and covered, as far as Victoria, with dark, rich, arable soil.

At Victoria we crossed the Guadalupe River, which is here about fifty feet wide, flowing between high bluff banks. Here I saw, for the first time since leaving Indianola, strata of older date than those of the Quaternary Period. They consist of laminated layers of soft, crumbling, reddish quartzose sandstone, with rounded silicious pebbles embedded, which are sometimes so abundant as to form a conglomerate. These strata appear only at a few points, forming ledges from four to five feet high, with a dip of 10 degrees southeast. They are surmounted by twenty-five feet of ash-colored loam, containing here and there small angular fragments of compact gray limestone.

I have been informed that about four miles south of this place extensive beds of soft gray limestone occur, that yield a good quality of quicklime, for which purpose they are extensively employed in the neighborhood. I was not, however, able to procure specimens of the rock for examination.

Distance, 16 miles.

April 6.-The prevailing formation encountered to-day was coarse reddish sand and sandy clay of the Quaternary Period, in places abounding with pebbles and small boulders of dark silicious rocks. Commingled with these also occur silicified fossil dicotyledonous wood, resembling in all respects specimens I obtained from deposits of the same geological age near the headwaters of the Brazos, Big Wichita and Red Rivers of Texas.

The fossil wood, as well as the pebbles and boulders, have doubtless been mainly derived from the destruction of Cretaceous strata.