CONTENTS. 



PAGK 



Introdiu'tion 137 



Part I. Glacial Gedlogy ami Gfiieral (Characters of the Illinoisi Sand Areas, 



especially those of Western Illinois. By (Uiarlks A. Hart 139-148 



Glacial Geology 139 



Topography: (-ieneral 144 



The Surface San<ls 145 



( Ither Sand Areas 1 46 



Part II. A Botanical Survey of the Illinois Kiver Valley Sand Region. By 



Henry Allan (tlkason 149-194 



Introductory 149 



Ei-ological Factors 149 



The Plant Associations 157 



The Bunch-grass .Vssociation 158 



The Blow-sand .\ssociation 102 



The Blowout Association 167 



Reversion to Bunch-grass I(i9 



The Black-jack Association 171 



Some Adaptations of the Plants to the Knvironnient 178 



List of the Plants Observed 181 



Phytogeograjihical Relationships of the Flora .' 189 



Part III. Zoological Studies in the Sand Regions of the Illinois and Missis- 



sipjii River Valleys. Bv Charles A. Hart 195-1!(J7 



( ieneral Features 195 



The Localities Visited 197 



Geographical Distribution of the Si)ecies 1 99 



Sand as a Factor of. Animal F^nvironment 208 



The Relation of Sand and Climate to Insect Coloration 211 



Local Distribution of Sjiecies in the Sand Areas. The Insect Associa- 

 tions 220 



Annotateild>ist of Species 227 



Systematic Notes 259 



Bibliograiihy 208 



