GENERAL DISCUSSION 



TABLE II. DISTRIBUTION OF AMERICAN LAND SHELLS 



NORTH OF LATITUDE 49. Continued. 



III. SUMMARY OF THE MOLLUSK FAUNA OF NORTHEAST- 

 ERN ASIA. 



The land shell fauna of the northeast extremity of Asia has 

 little individuality, but represents a mingling of the depauper- 

 ated extremes of the faunas of northeast China, and of Europe, 

 with that series of species which is sometimes called the circum- 

 polar or circumboreal fauna. 



