VI PKEFACE. 



plete collection (numbering some 15,000 specimens) of Costa Rican 

 birds belonging- to the National Museum of Costa Rica, at San Jose, 

 where a commodious and convenient workroom and free access to the 

 specimens were placed at his service; and it is also a great pleasure to 

 refer to the indispensable assistance rendered by Don Anastasio Alfaro, 

 Director of the Museum, and Don Jose C. Zeledon, of San Jose, 

 during the author's six months' sojourn in that country collecting 

 material for the present woi"k. 



The illustrations in this volume not previously published were 

 mostly made by Mr. H. W. Hendley, of Washington, District of 

 Columbia, and the measurements of specimens were made chiefly by 

 Mr. J. H. Riley, of the Division of Birds. 



Robert Ridgway. 



May 20, 1907. 



