THE OLIVE-SIDED FLYCATCHER. .339 



Flycatchers are formed throughout the tropical world, but 

 the Flycatchers of America are a peculiar and well differ- 

 entiated branch, some of which extend into north temperate 

 latitudes. They are so distinctively marked as to be readily 

 distinguishable from all other birds. Especially is this true of 

 that division of the family peculiar to North America, the 

 Tyrannidm. The great body of the nearly four hundred 

 species constituting the entire American group belongs to 

 Central and South America, and are exceedingly varied in 

 the details of form and color, some of them being very brill- 

 iant. Ours are merely the outlying and plainer varieties. 



Our North American Flycatchers, the Tyrannidce, may be 

 distinguished by their rather large head, the crown feathers 

 of which are more or less erectile; by the bill, which, broad 

 at the base, rapidly narrowing to a sharp point, and 

 depressed or flattened across the top and underneath, 

 appears triangular when viewed from above, the upper 

 mandible being hooked and notched near the tip, while the 

 mouth is provided with stiff bristling hairs on either side; by 

 the wing, the ten primaries of which are of full length and 

 narrowed, or emarginate near the end; by the feet and legs, 

 noticeably small and weak for the size of the bird; and by the 

 voice, which, for the most part, is harsh. Solitary in their 

 habits, they are generally brave, and, on account of their 

 strictly insectivorous habits, are very useful. 



THE OLIVE-SIDED FLYCATCHER. 



Belonging to this same genus, Contopus, is the Olive-sided 

 Flycatcher {Contopus borealis). About 7.50 long, hav- 

 ing the form of the Wood Pewee and the color of 

 the Common Pewee, or Phoebe, it is always to be 

 distinguished from the latter by its light-colored under 

 mandible, its dark olivaceous sides, and its " tuft of white^ 



