NATURAL SCIENCES OF PriILADELPHIA. 21 



Dendroeca palmarum. 



Rather frequeut, particularly late in the fall, in low shrubbery, 

 with the sparrows. 



Progne purpurea, 



Comiiion, March to October ; as man}' as can find accommoda- 

 tion breed about the fort. 



Hirundo horreorum. 



During the migration only ; then abundant. 



Hirundo bicolor. 



Abundant during the migration, Numbers made their appear- 

 ance Januar}'^ 11, 1870, on a warm da}', though there had been 

 ice a half inch thick two da3's before. They almost immediately 

 disappeared during some blustering weather, but reappeared in 

 greater numbers than before on the 20th, and were occasionally 

 seen from that time until the regular migration took place, in 

 April. 



Cotyle riparia. 



During the migration. 



Vireo novaeboracensis. 



Common summer resident of the shrubbery, April — October. 



Vireo olivaceus. 



Occasional!}' seen, during the migration. 



Pyranga aestiva. 



Frequent, in summer. 



Chrysomitris tristis. 



Common, in flocks, from November to April. Here it spends 

 much of its time on the ground, feeding apparently in greatest 

 part upon the seeds of Cenchrus trihuloides. 



Passerculus savanna. 



The characteristic sparrow ; very abundant everywhere out- 

 side the marsh itself, from October to May ; none remain through 

 the summer. Its numbers do not perceptibly decrease until the 

 middle of April, when the greater part move northward ; but 

 loiterers are seen through most of May. Their earliest connected 

 notes are heard late in March ; and they are in full song and 



1871.] 



