PAPERS OF GENERAL INTEREST 57 



1. Tundra or Barren Grounds (Arctic of Merriam) ; 

 Xorthem part of the continent, in X. E. United States 

 during glacial times. 



2. Xortbern Conifer Forest (Canadian and Hudson- 

 ian of Merriam except in the Pacific slope area) ; Xortb- 

 ern United States and Canada, extending southward into 

 the mountains where it has been designated as Mountain 

 Conifer Forest. 



3. The Xorthwestern Moist Conifer Forest (Van- 

 couveran of VanDyke) ; Pacific slope Xortbern California 

 to Alaska. 



4. Semi-desert Conifer Forest ; on the western desert 

 mountain slopes and foothills. 



5. Poplar Savanna; a narrow strip skirting the con- 

 ifer forest on the south and west ; Wisconsin to Alberta. 



6. Deciduous Forest; Eastern United States and 

 Southern Canada. 



7. Oak Grove Savanna; Mississippi Valley, — Illinois 

 was originally of this type. (See Figs. 10-13). 



8. Southeastern Conifer Forest ; S. E. United States, 

 near the coast. 



9. Grassland and Steppe ; the Great plains. 



10. Temperate Semi-desert Broken Steppe ; the Snake 

 River Valley, Xorthem Texas, and portions of Xew Mex- 

 ico. 



11. Mexican Plateau Desert; the Cbihuabua-Zacatec- 

 as area in Mexico. 



12. Extreme Desert (small leafed shrub desert) ; 

 Lower Colorado Eiver Area. 



13. Sage Brush Desert ; the Great Basin. 



14. Eastern Succulent Desert; West Texas. 



15. Western Small tree and Succulent Desert; Ari- 

 zona and Sonora. 



16. Mesciuite Semi-desert; Southern Texas and X. 

 E. Mexico. 



17. Broad-Leafed Evergreen Semi-Desert (CaUfor- 

 nian of Van Dyke) ; California. 



