1891] MARYLAND ACADEMY OF SCIENCES. 115 



dergrowth, where it is observed to fly from tree to tree as if in 

 search of insects. Its motion reminded me sometimes of the 

 darting of the flycatchers. The bird was formerly to be found 

 among the groves and copses bordering the Back and Patapsco 

 rivers, and did not appear at any time fond of running on the 

 ground. It remains continuously from about the 10th of May 

 until some time in the month of September. 



Dendroica aestiva (Gmel.). Yellow Warbler. 



Of the genus " Dendroica" proper, this is our most common 

 species, and the one which, owing to its habits, may be most 

 readily observed. The "Yellow Warbler" frequents small 

 trees and shrubs along the road, or willows and similar trees 

 along the water, and even visits our gardens and yards, especially 

 on its arrival, which is about the 24th of April. As early as the 

 second or third week in September, it takes its departure. 

 The notes, although not very remarkable, make a pleasant war- 

 ble, sounding something like the syllables dui-dia-dee. 



Dendroica discolor (Viell.). Prairie Warbler. 



One not acquainted with the notes of this little warbler 

 might readily conclude that it is a rather rare summec visitor. 

 Although not quite so common as the "yellow warbler," in 

 suitable localities it is abundant all through the summer. The 

 favorite habit of the bird is to hide in the foliage of some ever- 

 green, for example the cedar, but it does not adhere exclusively 

 to such trees, and betrays itself by the curious notes of its song. 

 The notes sound like the syllable " Ts," which gradually grows 

 higher and louder, and abruptly terminates with the syllable 

 <( Ee-a," pronounced with emphasis. The time of the arrival in 

 this locality is about the same as that of the " yellow warbler," 

 and the departure takes place in September. 



Dendroica vigorsii (Aud.). Pine Warbler. 



Early in April, the Pine Warbler makes its appearance, and 

 becomes more abundant throughout this month in all suitable 

 localities. Later on, the numbers greatly decrease, so that as 



