156 MNIOTILTIDA. 
Geothlypis philadelphia, 8. macgillivrayi, Ridgw. Am. Journ. Sc. ser. 3, iv. p. 459°; Lawr. Mem. 
Bost. Soc. N. H. ii. p. 269"; Bull. U.S. Nat. Mus. no. 4, p. 17. 
Geothlypis philadelphia, Scl. Cat. Am. B. p. 27 (nec Wilson)”. 
Sylvia vegeta, Licht. fide Bp. Consp. Av. i. p. 310”. 
Geothlypis, sp.?, Baird, Rev. Am. B.i. p. 227”. 
Precedenti similis, sed ciliis albis distinguenda, plaga pectorali quoque absente. (Descr. exempl. ex Guate- 
mala. Mus. nostr.) 
fab. NortH America, Middle and Western Provinces! 12—Mxxtico!7, Monterey 
(Couch”), Mazatlan (Grayson 1+), Jalapa (de Oca*), Orizaba (Sumichrast 3, Botteri'), 
Choapam and Cinco Sefiores (Boucard °), Chihuitan and Tehuantepec city (Sumi- 
chrast ©); Guatemala, Duefias 18, Coban? (0. 8S. & F. D. G.4); Costa Rica, San José 
(v. Hrantzius®), Barranca (Carmiol*); Panama, Volcan de Chiriqui (Arcé”). 
This species entirely takes the place of G. philadelphia in Mexico and Guatemala, 
where it is found during the winter months widely distributed over those countries, but 
chiefly hanging to the western or Pacific shore. In Southern Mexico it is found on 
both sides of the Cordillera; but in Guatemala, though it occurs at Coban 5, we most 
frequently met with it in the main range near Duefias, where it was abundant at an 
elevation of about 5000 feet. Beyond Guatemala it passes to Costa Rica and Chiriqui, 
where it is found in conjunction with its eastern ally G. philadelphia, in which 
limited area only these species come into contact, and only here during the winter 
months; for in summer the treeless plains east of the Rocky Mountains separate 
them by a wide interval. ‘The lines of migration of these two birds are very different, 
G. philadelphia taking a long flight over the ocean, G. macgillivrayi following in the 
main the course of the Cordillera. | 
Dr. Coues gives a good account of this species in his ‘ Birds of the Colorado Valley.’ 
In the States it is found only in the Middle and Western provinces, going as far north as 
British Columbia. Its eastern range is determined by the limit of arboreal vegetation 
along the Rocky Mountains. Throughout this range it breeds, its nest being built of 
various materials, sometimes mosses and sometimes various soft fibrous materials, such 
as bark-strips and frayed-out plant-stems with fine grasses, and lined with slender 
rootlets". ‘The eggs are white, spotted and blotched with very dark brown, reddish 
brown, and other markings of a neutral tint. 
The bird described but not named by Professor Baird in his ‘ Review of American 
Birds’ 1%, and attributed to a species of Geothlypis distinct from G. macgillivrayé, but 
unknown to him, would now appear to be G. macgillivrayi after all. Salvin examined 
the specimen at Washington in company with Mr. Ridgway in 1874; and this was the 
conclusion they came to. Similar specimens are in our collection obtained in precisely 
the same localities as fully plumaged birds, and associating with them. 
