Nothing further seems to have appeared in print regarding the habits of this warbler. It is much like the well-known parula warbler in appearance and behavior, but can be recognized in the field by the conspicuous black lores and cheeks and by the complete absence of any pectoral band. DISTRIBUTION _Range._--The species ranges from southern Texas to northern Argentina and Uruguay. The race occurring in the United States is found in southern Texas and northeastern Mexico. _Breeding range._--Sennett's olive-backed warbler breeds =north= to northeastern Coahuila (Sabinas); and southern Texas (Hidalgo, Harlingen, and Point Isabel). =East= to southern Texas (Point Isabel and Brownsville); and southeastern Tamaulipas (Altamira and Tampico). =South= to southern Tamaulipas (Tampico); and southern San Luis Potosí (Valles). =West= to eastern San Luis Potosí (Valles); and eastern Coahuila (Cerro de la Silla and Sabinas). _Winter range._--While probably not a sedentary form, its winter range very nearly coincides with its breeding range. It has been found in winter from Brownsville, Tex., to northern Hidalgo (Jacala). _Egg dates._--Texas: 6 records, April 28 to May 30; 4 records, May 2 to 12, indicating the height of the season. Mexico: 2 records, May 27 and July 5. PARULA GRAYSONI Ridgway SOCORRO WARBLER HABITS The Socorro warbler is closely related to Sennett's warbler and other races of _pitiayumi_ but is accepted as a distinct species. It differs from _nigrilora_ in having gray, instead of black, lores and cheeks, and in having much less white on the inner webs of the outer rectrices. It was supposed to be confined to Socorro Island, one of the Revillagigedo group, about 250 miles southwest of the southern tip of Baja California. It was added to our fauna by Chester C. Lamb (1925), who states: On November 3, 1923, I collected one of these birds at Todos Santos, on the Pacific Ocean side of the peninsula of Lower California, some forty miles north of Cape San Lucas. * * * On February 5, 1924, I saw another of these little warblers, within a few feet of me; but my gun was not at hand, so I had to be content with a sight record. The locality was inland, at El Oro, on the east side of the Victoria Mountains, about thirty miles from Todos Santos. The next occurrence, like the first, was at Todos Santos, where, on July 23, 1924, I secured an adult female which is now in my collection at the Los Angeles County Museum, Los Angeles. The taking of these two birds, in the winter and summer of two successive years, would indicate that the species is of more or less regular occurrence in the Cape Region of Lower California. The capture of a specimen in July suggests the possibility of breeding at the point of record. Nothing more seems to have been heard of the species since. And we know nothing of its habits. DISTRIBUTION _Range._--Socorro Island and the Cape region of Baja California.