

ADVERTISEMENTS. v 
FOSSILS. 
Cretaceous Invertebrata and 
Tertiary Vertebrata 
Of S. Dakota, Nebraska, and Wyoming, a 
pile by Cove: Marsh, Leidy, and Meek. 
Placenticeras, Nautilus, Scaphites, 
Baculites, Teredo, Turtles, Teeth 
and Skulls of the Titanotherium, 
Oreodon, Mesohippus, Acerathe- 
| rium, Hyracodon, Elotherium, Car- 
Hyracodon nebrascensis. | nivora, etc. 

Green River Fossil Fish ; fifty varieties Fossil Leaves of Dakota Group 
named by Lesquereux. Black Hills Minerais in large variety. Jndian Relies 
both ancient and modern. Large stock of everything. Send for illustrated 
catalogue with prices. Wholesale and Retail. Colleges, large collectors, 
amateurs, museums, and dealers supplied. 
E W STIEWELL, 
DEADWOOD, SOUTH DAKOTA. 
Mention AMERICAN NATURALIST. 
The Ives Strata w Altitude Maps 
OF THE UNITED SiAIES 
AND PART OF CANADA. 

Descriptive Circular, with Tes- 
timonials from Professors Dana, 
Shaler, Newberry, Cope, Winchell, 
Heilprin, President Gilman, and 
others, together with the inventor's 
“ Guide to Geology by Means ofthe 
Strata Map,” 
FERRIS BROS., Pustisuers, 
N. E. Cor. 7th and Filbert Streets, 
The American Naturalist. Philadelphia. 
