Note 75 — Family VIREONIDÆ.—The Vireos.

V. gilva var. josephæ. Vireosylvia josephæ, Baird, Rev. 1865, 344 (Vireo josephæ, Sclater, P. Z. S. 1859, 137, pl. cliv). Comparing typical examples of this “species” with those of gilvus from North America, they appear very widely different indeed, so far as coloration is concerned, though nearly identical in form. But a specimen from an intermediate locality (54,262, Orizaba, Mexico, F. Sumichrast) combines so perfectly all the characters of the two, that it would be impossible to refer it to one or the other as distinct species. It therefore becomes necessary to assume that the V. josephæ is a permanently resident tropical race of a species of which V. gilvus is the northern representative; which theory is strengthened by the fact that of the latter there are no specimens found south of the United States, indicating that in winter it does not pass beyond their limit, or at least not far to the southward.