place of our encampment, on the left, we passed the Swallow (or Hirundel), rocks, a projecting cliff, about 150 feet high, adorned with bushes of cedar, in the centre of which there appears to be an entrance into a cavern, and several other fretted excavations scattered over with clusters of martin nests. The rock consists of two beds; the upper a lighter coloured ferruginous and laminated sand-stone, excavated with appearances similar to nitre caves; the lowest bed, with a more considerable dip (about 10° to the south-*east), consists of thinner greenish grey lamina, containing a little mica, and exhibiting the usual zoophytic carbonaceous impressions, indicative of coal. The river bars now abound in gravel, which is principally petrosiliceous. After passing Cajou creek, on the left, about two miles, we encamped near a bar, to avoid the visits of the musquetoes, our progress to-day being about 24 miles.
8th.] Four miles further we again obtained a view of Point de Sucre and the Cavaniol. On Sambo island, about 12 miles from our departure this morning, we stopped to dine; and here on a bar of gravel I found a new species of the Mexican genus Stevia, and never saw it afterwards in any other locality. To {167} the taste it was quite as bitter as many of the Eupatoria. This plant, and the Portulaca already mentioned, appear to have been recently, and almost accidentally, disseminated from the interior. The cane still continues abundant, and the alluvial lands are extensive and fertile, with a basis of sand-stone, which two miles below appears in the same dark and ferruginous rocky mass as near Skin bayou. On some of our party going out a hunting, we concluded to spend the remainder of the day on the island.
9th.] This morning we crossed the river to the mouth of Sambo creek, and went out into the neighbouring prairie
