Geology and Mineralogy. 155 
semys, Eimys ; of Rhynchocephalia, 4 species; Batrachia Uro- 
dela, 5; others of Lepidosteus, and Ceratodus. 
Mr. Cope makes the Lignitic formation include the Judith 
River and Fort Union epochs, as defined by Meek, and regards 
the Laramie or Bitter Creek beds as representing other epochs. 
_ Prof. White discusses the age of the Lignitic group in connec- 
tion with his review of the species of fresh-water and land shells, 
He refers the Judith River and Laramie groups to the Post- Cre- 
Mountain areas, Upper Cretaceous; the eruptions were certainly 
th Park View Mountain and Spanish Peaks, 
nitic strata are intersected by trachytic dikes. Dr. Peale con- 
sa 
Morphie rocks lying beneath—the fusion being due to the heat 
eccasioned by the movements and plication. 
A Fourth edition of the “Lists of Elevations” by H. Gannett 
S been issued. It contains the Hypsometric map noticed on 
Page 387 of the last volume of this Journal. 3 
