ILLUSTRATIONS. 
Plate I-III. Appendages of the First Abdominal 
Segment of Embryo Insects. opposite page 140 
Plate IV. Passage of Gabbro-Diorite into Horn¬ 
blende Gneiss at Ilchester, Md. opposite page 160 
Plate V. Map of a Region in Northwestern Mon¬ 
tana. opposite page 187 
Plate VI. Map and Profiles of Green Lake. opposite page 218 
Plate VII. Sections from Ore Deposits of the Lake 
Superior Region. opposite page 228 
Plate VIII. Map of the Western Erie Basin and 
Adjacent Territory. opposite page 235 
Plate IX. The Behistan Mountain. opposite page 242 
Plate X. The Tomb of Darius. opposite page 261 
Plate XI. Diagram Showing Effect of Temperature 
in the Distribution of Magnetism.... opposite page 288 
Plate XII. Effigy Mounds in Wisconsin. opposite page 300 
Plate XIII. Crustacea Cladocera from Madison, Wis. opposite page 398 
Portrait of Roland Duer Irving . opposite page 433 
Portrait of William Francis Allen . opposite page 439 
