198 VIREONID2. 
birds here at this time of year indicates that they breed in some more northern locality, 
which, however, has not yet been traced. The difference between V. cassini and 
V. solitarius is but slight, and consists chiefly in the head of the former being almost 
the same colour as the back instead of grey, and in the breast being tinged with fawn 
colour. These differences are blended by intermediate specimens, according to writers 
on North-American birds?; but the extremes are sufficiently varied to justify each 
bearing a distinctive title. 
12. Vireo plumbeus. 
Vireo plumbeus, Coues, Pr. Ac. Phil. 1866, p. 747; B. Col. Vall. i. p.515°; Lawr. Mem. Bost. Soc. 
N. H. ii. p. 272°. 
Vireosylvia plumbea, Baird, Rev. Am. B. i. p. 349 *. 
Lanivireo solitarius, var. plumbeus, Baird, Brew. & Ridgw. N. Am. B.i. p. 877’. 
Supra plumbeus, oculis albo conspicillatis ; alis et cauda nigris, extus albo limbatis, illis albo bifasciatis ; subtus 
albus, hypochondriis plumbeo lavatis; rostro et pedibus plumbeis. Long. tota 5:0, ale 3:3, caude 2:3, 
rostri a rictu 0°6, tarsi 0°72. (Deser. exempl. ex Oaxaca, Mexico. Mus. nostr.) 
Hab. Unitep States, Southern Rocky-Mountain region 2°, Arizona }.—Mexico, plains of 
Colima (Xantus??*), Oaxaca (Fenochio). 
The position of this bird appears to be not yet fully established, American orni- 
thologists, to whom it is best known, differing as to whether it should be granted full 
specific rank as V. plumbeus, which is Dr. Coues’s (its discoverer’s) view, or whether it is 
still linked with V. solitarius, and should stand as V. solitarius plumbeus, as maintained 
by Mr. Ridgway in his recent list of North-American birds (1881). Be this as it may, 
the normal V. plumbeus is a bird easily to be distinguished from V. solitarius, and 
therefore entitled to a name. 
As already stated, Dr. Coues discovered this bird, near Fort Whipple in Arizona |, 
where he found it in pine-woods during the summer, replacing V. solitarius at that 
season of the year. It has also been traced to Laramie Peak 1, Colorado, New Mexico, 
and Utah, thus embracing the southern portion of the Rocky-Mountain region. The 
only recorded instance of its occurrence in Mexico is based upon a specimen obtained 
by Xantus in the plains of Colima in February 1863224; but we now have to mention 
a second Mexican locality some distance further south, a specimen having been sent us 
some time ago from the vicinity of the town of Oaxaca by Don A. Fenochio. | 
Little is recorded of the habits of V. plumbeus, which are said to resemble those of 
V. solitarius. The nest and eggs taken by Mr. Aiken in Colorado are stated to be 
substantially identical with those of its near ally. 
