WARBLING VIBEO. 301 
isfactorily, I find that in all of the numerous North American genera examined, those of 
ten primaries show but one of these little feathers, while the rest have two. In the 
family Alaudide, as in Vireonide, some genera have ten primaries, others apparently only 
nine; and ig our genus Hremophila, in which only nine are developed, there are two of 
the little feathers just mentioned, the overlying one being exactly like one of the pri- 
mary coverts, the other, though not very similar, more resembling an abortive primary. 
Alauda arvensis, which shows a minute but obvious spurious quill, has but one such 
little feather; and in Galerita eristata, with a spurious quill about two-thirds of an inch 
long, there is likewise but one. In Clamatorial Passeres, perhaps withont exception, 
there are ten fully developed primaries, the first of which may equal or exceed the next 
in length; and in the single North American Clamatorial family, Tyrannide, 1 tind, as 
before, only one of these little feathers. In a Woodpecker, remarkable among Picarian 
birds for possessing only nine long primaries, the first being short or spurious, there is 
also but one. | 
It thus seems to be established that amoug supposed nine-primaried birds, the addi- 
tional one, making ten in all, is normally represented by the secoud one of these tiny 
quills which overlie the base of the outermost fully developed feather ; it being the same 
little quill which in ten-primaried Oscines, in Clamatores, and probably other birds, comes 
to the front and constitutes the first regular primary, either remaiulng quite short, when 
it 1s the so-called ‘‘spurious” primary, or lengtheving to equal or excee. the over pri 
Inaries in extent. 
It becomes an interesting question whether both of these minute quills be not rudi- 
mentary primaries, as one of them certainly is. I have failed to detect any material 
difference between the two in size, shape, or position. One overlies the other, indeed, as 
a covert should a primary, bat the two are together inserted side by side on the upper 
side of the first fully developed quill; both are rigid and acuminate, more like primaries 
than like coverts, and both are abrupily shorter than the true primary coverts. So far, 
all the evidence favors the supposition that both are rudimentary primaries. On the 
other hand, coloration is against suck hypothesis, as in the original case of Vireo flavi- 
frons, in which Baird determined the underlying one of these two little feathers to be 
the missing primary, mainly because it was colored like the primaries, the overlying one 
resembling the coverts in coloration. But the color test is often inapplicable, coverts . 
and primaries being usually like each other in this respect, and color sometimes pvints 
the other way. ‘hus, in Sttta carolinensis, a ten-primaried Oscine with spurious first 
primary, the single remaining little feather is white at base across both webs, like the 
primaries, the true primary coverts being white only on the inner web. 
VIREO GILvus (V.) Bp. 
Warbling Vireo. 
Vireo gilvus, KIRTLAND, Ohio Geolog. Surv., 1838, 183, 180 —Reap, Fam. Visitor, iii, 1853, 
383; Proc. Phila. Acad. Nat. Sci., vi, 1853, 395.—WHEATON, Ohio Agric. Rep. for 
1860, 364; Reprint, 1861, 6; Food of Birds, ete., Ohio Agric. Rep. for 1874, 565; 
Reprint, 1875, 5.—LANGDON, Cat. Birds of Cin., 1877, 7. 
Vireosylvia gilvus, LANGDON, Revised List, Journ. Cin. Soc. Nat. Hist., i, 1879, 174; Re- 
print, 8. 
Warbling Vireo, BALLOU, Field and Forest, iii, 1878, 136. 
Muscicapa gilva, ViEiLLoT, Ois. Am. Sept., i, 1807, 65. 
