Nov. 1907. BIRDS FROM GUATEMALA DEARBORN. 73 



Thanks are due, and are hereby heartily rendered, to Mr. F. G. 

 Williamson, General Manager of the Guatemala Northern R. R., and 

 Col. W. P. Tisdel, Assistant Manager of the Guatemala Central R. R., 

 for assistance in transportation; to Consul General Winslow and 

 Vice Consul Owen, both of whom did all in their power to give assist- 

 ance, which on at least one occasion was sorely needed; and to Mr. 

 William Mac Farlane, Sr. Don Guillermo Peitzener, Sr. Don Frederico 

 Miiller- Winter and Sr. Don Guillermo Thom for hunting privileges 

 and hospitality. 



It is also a pleasure to acknowledge the kindness of Dr. J. A. Allen, 

 of the American Museum of Natural History of New York, Prof. 

 Robert Ridgway, of the Smithsonian Institution, and Dr. C. Hart 

 Merriam, Chief of the Biological Survey at Washington, in allowing 

 specimens to be sent from the collections in their charge to aid in 

 the study of this collection; and to Mr. E. W. Nelson, Chief Field 

 Naturalist of the Biological Survey, whose knowledge of the birds 

 of Mexico is unequaled, for advice on several doubtful points. 



In the following notes, particular attention has been given to dates 

 of capture of such specimens as were migrants from North America, 

 and to all cases of moulting. There are few data published relating 

 to the time when such birds as have a distinctive nuptial plumage 

 acquire it. It may be here remarked, that the resident birds were 

 very rarely found to show any signs of a spring moult, while the 

 migrants taken in April and the latter part of March, as a rule were 

 putting out new feathers. Cases of individual variation have been 

 mentioned, and, while the naturalist bent on collecting, finds scant 

 time to study habits, such as were apparent have been recorded. 

 Colors are designated, as far as possible, according to Ridgway's 

 Nomenclature of Colors. 



Family Podicipedidse. 



1. Colymbus dominicus brachypterus Chapman. 



Seven specimens were taken at Lake Atitlan between March 4th 

 and April pth. Only one of them, a female, was in nuptial plumage. 

 Two other females, which were assuming the breeding dress, had the 

 chin white and the throat black ; showing that the progress of moult 

 on this area is towards the bill. One of the males had shed all the 

 primaries of both wings, the pins for the new primaries being about 



