DIONS ACROSS THE GREAT BASIN OF UTAH. 



shell described by Professor Hall, in Fremont's report, under 

 tm, might be one of the Bear River species of Goniobasis, and 

 1 by him in the same report, under the names of Naticaf occi- 

 '.afonnis, might be the young of a Vivlparus found at the Bear 



ue can be fortunate enough to be able to make comparisons 



ttg this report, all of the facts known seem to favor the con- 



ni series mentioned above occupies an extensive area in the 

 am informed by Mr. Engelmann, that it is mainly made up of 

 irenaceous shales, with some calcareous beds, several hundred 

 li no organic remains were found. Beneath these beds, how- 

 -colored shales and limestones, containing great numbers of 

 species, all of which are fresh- water types. Those collected 

 ■ies of Mvhui'M, two of Limnra, one of Unio, and three of 



way with those of the Upper Missouri; that is. tl.ev consist of ;m nldei- JerL o^ Wk 

 water origin (probably in local isolated basins), succeeded by fresh-water formati< 



in these Utah [and Wvmni ,g] Tertian iormatilms mv 1,'iul iar^s kliown, specitic- 

 distinct from those characterizing the Upper Missouri beds, excepting a single spe< 

 of Viriparus already mentioned ( V. Cumuli, Meek and Hayden), which is commoi 

 the Sulphur Creek estuary deposits, \ and those of the Upper Missouri, near the mo 

 of Judith River. Still, it is probable that we have not yet obtained facts enougl 

 be able to determine whether or not these formations correspond in their details^ 

 those of the Upper Missouri. 



From what lias been said, it will be seen that all the fossils contained in the < 

 Action from localities along the line of the survey, in the Great Salt Lake Basin, 

 from Paleozoic rocks; while all those from Secondary and Tertiary formations w 

 collected from localities east of the Wahsatch range of mountains.§ 

 Very respectfully, yours, &c, 



F. B. Meek. 



r group (November, 1875). 



