169 



appear that their interception occurred somewhere near the mouth of 

 the Hudson, thus including New York city and vicinity in the angle 

 formed by their divergence. The northern limit of the Hudson Eiver 

 branch is as yet undetermined." 



Then follows an enumeration of the species, belonging to this cate- 

 gory, which Mr. Bicknell has discovered in the neighborhood of River- 

 dale, which are as follows : Mimus polyglottus (Mocking Bird) ; Lopho- 

 phanes bicolor (Tufted Titmouse) ; Thryothorus ludovicianus (Carolina 

 Wren); Helmitherus vermivorus (Worm-eating Warbler); Helmitho- 

 phaga pinus (Blue- winged Yellow Warbler) ; Helmithophaga chrysop- 

 tera (Golden-winged Warbler) ; Oporornis formosus (Kentucky War- 

 bler) ; Myiodioctes mitratus (Hooded Warbler) ; Stelgidopteryx serri- 

 pennis (Rough- winged Swallow) ; Cardinalis virginianus (Cardinal 

 Red-bird) ; Corvus ossifragus (Fish Crow, seen, but not captured) ; 

 Empidonax acadicus (Acadian Flycatcher) ; and Strix flammed (Barn 

 Owl, seen, in New York city, by Mr. H. B. Bailey). 



That this Carolinian tinge extends for a considerable distance up 

 the Hudson, not only to the Highlands, but through, and a little 

 .beyond, I shall be able to show in the following list. Unquestionably, 

 we owe to the Hudson River the possession, as abundant summer resi- 

 dents, of such species as Helmitherus vermivorus, Helminthophaga 

 pinus, Siurus motacilla, Icteria virens, and several other species, which 

 accession gives to our avi-fauna its Carolinian tinge; it belonging, 

 otherwise, to the division of country known as the Alleghanian Fauna. 



To map out the exact dividing lines of the different faunal areas, is 

 one of the most important and attractive branches of zoological re- 

 search ; while the labor of determining the precise range of habitat 

 for each species, is, indeed, an arduous task, and one that, from its 

 importance, must claim a large share of the attention of our ornithol- 

 ogists for many years to come. 



The present list of our birds is intended to embrace only those spe- 

 cies which have actually been captured within the described limits ; or 

 those which have been seen under circumstances which admit of not 

 the slightest doubt of the accuracy of the observations. To this enu- 

 meration is appended a separate list of the species whose occurrence 

 is probable especially such as have been observed in contiguous dis- 

 tricts. 



It seems unnecessary to discuss, at any great length, the problem 

 of the extinction of a number of species that were formerly abundant; 

 but are not now to be found at all within our limits. I will, therefore, 

 simply mention that several species have only disappeared within the 

 past few years, while others have long since passed away. Among 

 the former, were two of our most prized game birds, the Wild Turkey 

 (Meleagris gallopavo'), and the Pinnated Grouse or Prairie Chicken 



