OF EASTERN PENNSYLVANIA. 63 



strays from the other, as soon as it becomes con- 

 scious of the fact, it utters its usual call-notes 

 which are instantly responded to by the other, 

 when within hearing distance. A similar succes- 

 sion of notes is heard when a booty is discovered 

 to which it desires to summon the other. We are 

 informed by a friend of considerable experience, 

 and whose reliability is unquestioned, that other 

 species frequently respond to these calls. 



Its flight is high, well sustained, and character- 

 ized by notable firmness and celerity. 



The syllables tsckica-dee-dee-dee repeated quite 

 loudly and with a clear, distinct, and resonant ex- 

 pression, are often heard in the intervals of feeding. 

 Whet* alarmed even by the movements of the 

 squirrel or other small animals, these notes are 

 exchanged for the hoarse cries of day-day-day 

 which are often taken up by many individuals at 

 once, producing a perfect medley of inharmonious 

 sounds. 



The food of the Black-cap consists principally 

 of insects. Their eggs, larvce and images are 

 sought after and devoured with avidity. Even 

 chrysalides, however large, do not resist its 

 assaults. The following beetles constitute a con- 



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spicuous portion of its diet: Rynchceus pint, Bos- 

 trichus pini, Cratonychus coinpar, C/iryso.meia 

 cceruleipennis, Platynus cnpripennis, Harpalus cal- 

 iginosns, and others. Among lepicloptera, Clisio- 

 campa Americana, Anisopteryx vcrnata and other 

 geometers, besides many of the Noctnidcc and 



