XVI THE CHICAGO ACADEMY OF SCIENCES. 



Page. 



G. atkaensis (Dall) 4.")7 



Subgenus Polyrhytis Meek 458 



G. utahensis (Call) 458 



Subgenus Leptolimn^a Swainson 460 



Spurious and Unidentifiable Species 462 



Bibliography 468 



Description of Plates 511 



Errata 533 



Index 534 



