OF EASTERN PENNSYLVANIA. 3 



ally assume the leading position. Here we will 

 follow usage. 



Family Turdidae. Thrushes. 



The nostrils are nearly or quite oval, but un- 

 covered by feathers. In all our genera, there ex- 

 ist bristles about the rictus and base of superior 

 mandible. The toes are deeply cleft; the inner 

 one nearly to its base, and the outer to the ex- 

 tremity of its basal joint. There are twelve caudal 

 feathers, ten primaries, of which the first is 

 considerably abbreviated or spurious, and the 

 second shorter than the fourth. The two subfami- 

 lies of our fauna are rigidly defined by the character 

 of the tarsus. 



Subfamily Turdinae. Typical Thrushes. 

 The Typical Thrushes are easily distinguished 

 in the adult condition by the continuous plate, 

 formed by fusion of all the scutella, except -some two 

 or three just above the toes which envelop the tar- 

 sus. Upwards of one hundred and fifty species are 

 ordinarily assigned to this subfamily, principally 

 referable to the genus Turdus with its subgenera. 

 They are nearly cosmopolitan, and attain a con- 

 siderable development in subtropical America 

 where the subfamily is represented by forms in- 

 timately related to the Turdus proper. More 

 aberrant types of different genera are found in the 

 old world. In the United States we have but one 

 genus, to which the Robin belongs, and which em- 

 braces several common and familiar species. They 



