NATURAL SCIENCES OP PHILADELPHIA. 493 



the sides of the breast are rufous, the jugulum is unbarred, and 

 the bars of the lower parts are broad, distant, and brownish-black 

 upon a buff ground. 



There can be no question as to the proper specific name of this 

 species, the Sparvius ruficollis of Vieillot, and the Falco xantho- 

 thorax of Temminck being unmistakably the adult in the rufous 

 plumage. Whether the Sparvius gilvicollis of Vieillot is this bird 

 in its gray plumage (=31. leucauchen, Scl. and Salvin, nee Falco 

 leucauchen, Temm.?), is a question which can only be decided by 

 reference to Vieillot's type, should it yet exist. It probably is 

 this bird, however, or the one which we name 31. pelzelni (see 

 p. 494), for it certainly is not the 31. concentricus of Pelzeln, as 

 we fully demonstrate under the head of that species. 



The Falco leucauchen of Temminck cannot be identified with 

 certainty from his figure or description. The latter comes near 

 the young of the rufous phase of the present species, while the 

 specimens of the latter have usually been labelled with that name. 

 As we recollect them, 1 the specimens in the museum of the Phila- 

 delphia Academy, which were called 31. leucauchen,' 1 agree exactly 

 with a specimen now before us, belonging to Mr. Salvin's collec- 

 tion, and which we regard as unquestionably tlie young of the 

 plumbeous phase of 31. ruficollis, called by Sclater and Salvin 

 31. leucauchen. But notwithstanding all these circumstances, 

 which together favor the probability of the correctness of the 

 identification, there are several points in Temminck's plate which 

 cannot be reconciled to the young of the species under considera- 

 tion, although it is fair to presume that these discrepancies may 

 have resulted through a faulty representation of the type specimen. 

 Upon examining this figure it will be noticed that the first char- 

 acter which attracts attention is the stripe of white spots over the 

 eye, on each side of the crown, and down each side of the nape. 

 These markings we cannot find in any specimens of ruficollis ; 

 while the latter have a distinct nuchal collar of white spots, not 

 represented in the plate. The crown in this figure is colored rusty 

 brown, like the back, whereas in ruficollis it is either plumbeous 

 or, as is very rarely the case, blackish. The plate fails to show, 

 too, the well-defined half-crescent behind the brownish ear-coverts, 



1 Unfortunately we have now no opportunity of comparing them. 



2 See Proceedings of the Boston Society of Natural History, XVI, May, 

 1873, pp. 35, 40. 



