Dimensions. Length, 5.20; extent, 8.50; wing, 2.90; tail, 2.25; culmen, .50.
Habitat. Arizona and New Mexico.
Four additional specimens offer no variations affecting any of the characters above detailed.
In its generally dull, grayish coloration, with little trace of olive or yellow shades, this Vireo is curiously like V. pusillus, but the under parts are obscured with brownish, while the differences in size and proportions are too evident to require detailed comparison. From the smaller, much brighter-colored V. huttoni, which is unmistakably its nearest United States relative, it may be distinguished by the following diagnoses.
V. huttoni.—Wing, 2.28 to 2.37. Olive-green above and olivaceous-yellowish beneath. No clear white anywhere.
V. huttoni stephensi.—Wing, 2.55 to 2.90. Grayish-ash above with no decided olive-green excepting on the rump and tail. Beneath brownish-white, untinged with yellowish excepting on the sides and crissum. Wing-bands pure white and nearly confluent.
It will be observed that the above differences are closely parallel to those which separate Vireo belli and V. pusillus, while they are in no respect less important. Indeed were I disposed to emphasize certain peculiarities presented in the wing-formula of my type, it would not be difficult to make out an equally good case of specific distinctness, but unfortunately, the relative length of the wing-quills (including the spurious primaries) proves to be quite as variable in V. huttoni and its Arizona race, stephensi, as I find it to be in V. pusillus and V. belli, and, I might add, in all closely allied species which I have so far studied. In short, I am convinced that this feature, if ever of any diagnostic value, is so with only a small proportion of the birds to which it has been so freely and confidently applied.
In naming this Vireo after its discoverer, Mr. F. Stephens, I have paid but a deserved compliment to that gentleman’s zeal and energy as a field ornithologist. He notes the bird as “not uncommon in scrub oaks” among both the Chiricahua and Santa Rita Maintains. He also writes me that he has taken specimens in New Mexico, where, near Fort Bayard, a nest with four eggs was obtained in 1876. In both Territories it seems to be confined to the mountain ranges, where it undoubtedly breeds in all suitable localities.
41, ♂ ad., Morse’s Mill, Chiricahua Mountains, March 14. Length, 5.20; extent, 8.50; wing, 2.90; tail, 2.25; tarsus, .73; culmen, .50; depth of bill at nostrils, .15. “Iris brown.”
50, ♂ ad., Morse’s Mill, March 16. Length, 4.90; extent, 8; wing, 2.55; tail, 2.20; tarsus, .73; depth of bill at nostrils, .15.