Rocky Mountains. 107 



Some days passed, after our arrival at Fort Osage, before 

 the weather admitted our making the astronomical observa- 

 tions necessary to ascertain its position. The mean of the 

 results of several observations of the meridian altitude of the 

 sun's lower limb gave 39° 9' 33 1-2" north, for the latitude 

 of the place. 



A dark coloured carbonate of Kme, containing 1 small Terebratulae like 

 the T. ovata of Sowerby. but less than half as long. 



No. I. — A mass of carbonate of lime, containing segments ofencrinites 

 in small ossicula. 



6.— A Caryophylla of a single star, about 4 inches long, of an irregu- 

 larly 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 mid- 

 dle than the oval vertebra of an encrinite represented by Parkinson, Vol. 

 2. pi. 1.3, f. 40 — resembling those of the genus Plalycrinites of Miller. 



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