*4.<iO per Year Foreign). 36 ete. per Top.v. 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 



DEVOTED TO THE NATURAL SCIENCES 



IN THEIR WIDEST SENSE. 



Vol. XXVI. JANUARY, 1892. ~^~ No. 301. 



CONTENTS. 



H INFLUENCE TOPOGRAPHICAL 



AGE. 



; of the Limit of Glaciation— Cretaceous Fossils from 









|>N PROBLEMATIC ORGANISMS. Joseph F. James. 

 §The Shell- Bearing Mollusca of Portage 





; Boulder Trains and Boulder Belts— Geological News 











Ceremonial Circuit of the Cardinal Points. 





-GeneSr ^"^ " " : )3 



24 



B tauy —Notes on the Flor.) of Western South 



Dakota go 



Z <iogy. "- ' estodes — 



Clarence M. Weed. 



32 





37 



- sites in the 





:59 







San Diego Cs nee of an 



n— Exploration"^ 



41 



" - . . . ' : >■ ■■,.. ' 



§• Geology and Paleontology.— The Earthquake in 





fexas— The Arachnoid 



Geological Survey 







- of Pacific Coast 













:■■■ ■■ ■ " ;■ sv, . .. • -... 





PHILADELPHIA, U. S. A. 



BIXDEE & KELLY, 



Sta and 520 MINOR STBCPT 



