INTRODUCTION. 



When it is not expressly stated to the coutvaiy, the type specimens figured 

 have been presented to the U. S. National Museum collection by the gentlemen 

 whose names are given. Without mentioning each by name, my thanks are due 

 to the many friends whose assistance has so greatly aided me in the preparation 

 of this volume and added to its completeness, and whose cooperation will, I hope, 

 be continued until the work is finished. 



The original water-color drawings from which the plates have been repro- 

 duced were made by Mr. John L. Ridgway, of Washington, D. C, to whose 

 skill and painstaking care the excellence of the illustrations is lai'gely due. 

 The chromolithographic reproductions of these plates were made by the Ket- 

 terlinus Printing Company, of Philadelphia, Pa., and it gives me pleasure to 

 say that they are as faithful copies of the original drawings as it is possible 



to make. 



The Author. 



