At the distance of eleven miles we crossed a small river, flowing with a very gentle current over a gravelly bed, with a breadth of fifty or sixty yards, and an extreme depth of three feet; we have named {83} it _Little Neosho_, or _Stinking Fork_.[115] Its western bottom is of very considerable width, well wooded with the before mentioned description of trees, in addition to which the hackberry here first appears, and supporting a crowded undergrowth of pea-vines, nettles, and rank weeds, which obstruct the passage of the traveller. The eastern bank, upon which our noon-day encampment was established, was high rock and precipitous, requiring considerable exertion to surmount it. Here the organic reliquiæ are somewhat more distinct than those which we examined on the opposite side of this secondary river. They are referable to those generally extinct genera that inhabited the great depths of the primeval ocean. Amongst them we recognized a smooth species of anomia of the length of half an inch, a species of terebratula, an encrinus, and numerous insulated species of a Linnæan echinus. At two o'clock pursued our journey, under an extreme heat of 92 degrees, which was hardly mitigated by the gentle fanning of a slight S. E. breeze. The appearance of the country here undergoes a somewhat abrupt change. Low scrubby oaks, the prevailing timber, no longer exclusively restricted, as we have hitherto observed it, to a mere margin of a watercourse, now was seen extending in little clusters or oases, in the low grounds. In the ravines, which are numerous, profound, abrupt, and rocky, we observed the hickory (caria of Nuttall), which had not before occurred since our departure from the forest of the Missouri. The bluffs are steep and stony, rendering the journey much more laborious to our horses, that were almost exhausted by traversing a plain country, and their hoofs, already very much worn by constant friction with the grass, will, we fear, be splintered and broken by the numerous loose and angular stones which they cannot avoid. Near the summits of some of these bluffs the stratum of rock {84} assumes an appearance of such extraordinary regularity, as to resemble an artificial wall, constructed for the support of the superincumbent soil. At the distance of eight miles from the small river before mentioned we encamped for the night, on the east side of a creek which we call _Little Verdigrise_.[116] It is about forty yards in breadth, and not so deep as the Little Neosho; its bed is gravelly, but the foot of each bank is so miry that we experienced some difficulty in crossing. There is but a slight skirting of forest, which denotes to the distant spectator the locality of this creek.