4 PREFACE. 



Birds, and iu the preli&inary key to the ordeis of Birds. Dr. 

 COUES has also kindly placed at my disposal the ad vauce - sheets 

 of his yet unpublished monograph of American Bats. 



I am also under obligations to Messrs. BAIRD and RIDGWAY, 

 whose writings have been to me of essential service; to Prof. 

 COPE, whose numerous papers have been of great value in the 

 systematic arrangement of the Fishes, and whose check list of 

 the Reptiles and Batrachiaus has been closely followed in the 

 classification of those groups ; to Prof. GILL, \vhose arrangement 

 of the families of Fishes has been, with few modifications, 

 adopted in the present work ; to Dr. GUNTIIER, whose Catalogue 

 of Fishes is the vade-mecum of the working ichthyologist; to 

 Prof. RICHARD BLISS, Jr., who has generously aided me in the 

 identification of the Ichthelidae, in advance of the publication of 

 his monograph of that most difficult group ; to Mr. E. W. NELSON, 

 of Chicago, who has kindly furnished me with a yet unpub 

 lished list of the Birds and Reptiles of Illinois; to Prof. F. W. 

 PUTNAM, Dr. B. G. WILDER, and Dr. C. C. ABBOTT, for the loan 

 of books and other aids ; to Prof. H. E. COPELAND, for help of 

 various kinds, particularly in the verification of descriptions, 

 and to the many collectors and compilers of local lists, who 

 have freely placed their material at my disposal. 



Our knowledge of the geographical distribution of many 

 animals is still veiy imperfect. Quite a number of Southern 

 and Western species, here excluded as extra-limital, will prob 

 ably yet be found within the region included in this work. 



Additions and corrections of every character are earnestly 

 solicited from naturalists and teachers. 



D. S. J. 



INDIANAPOLIS, IND., May, 1876. 



