[136] Fort Osage was surrounded by a tract six miles square. It was the only government trading factory west of the Mississippi. The post was occupied at intervals until 1827, when it was superseded by Fort Leavenworth and permanently abandoned. The site was near that of the present town of Sibley, Jackson County, which was named in honor of George C. Sibley (see volume v of our series, note 36), who was (1818-25) government agent at Fort Osage. The distance above Chariton River, by the government survey of the Missouri, is a hundred and twenty miles. See our volume v, note 31.--ED. [137] A sketch of Boone as a Missouri pioneer will be found in Bradbury's _Travels_, in our volume v, note 16.--ED. [138] From Fort Osage. _Productus spinosus_, SAY.--Longitudinally and transversely subequally striated, the transverse striæ somewhat larger than the others; a few remote short spines, or acute tubercles, on the surface, arising from the longitudinal striæ. Breadth an inch and a half; the striæ are somewhat indistinct-- as in No. 5. _Productus incurvus_, SAY.--Shell much compressed; hinge margin nearly rectilinear; surface of the valves longitudinally striated; convex valve longitudinally indented in the middle; the beak prominent and incurved at tip; opposite valve with a longitudinal prominence in the middle; the beak incurved into the hinge beneath the other beak, and distant from it. Width more than 2-2/5 inches. A few univalves also occurred, but they were so extremely imperfect that their genera could not be made out. A dark-coloured carbonate of lime, containing small Terebratulæ like the T. ovata of Sowerby, but less than half as long. No. 1. a mass of carbonate of lime, containing segments of encrinites in small ossicula. 6. A Caryophylla of a single star, about four inches long, of an irregularly transversely undulated surface, imperfect at each end, but seems to have been attached at base. Near the base it is bent at an angle of about 45 degrees. Some small and young specimens of the Terebratula, like T. subundata of Sowerby. Miliolites centralis. SAY. 12. Astrea. A species of very minute alveoles. From the state of the petrifaction no radii are perceptible, so that the genus is not determinable. Saltworks near Arrow Rock. Columnar segments of the Encrinus. Inferior portion of the head of A. Pentramea. SAY. Segments of the column of an oval encrinus, much narrower in the middle than the oval vertebra of an encrinite represented by Parkinson, Vol. 2. pl. 13. f. 40.--resembling those of the genus _Platycrinites_ of Miller.--JAMES. {100} CHAPTER VI Mouth of the Konzas--Arrival at Wolf River--Journey by land from Fort Osage to the village of the Konzas.