Baird, Brewer, and Ridgway (1874) say: "The notes of Mr. Kennicott and the memoranda of Messrs. McFarlane, Ross, and Lockhart attest the extreme abundance of this species in the farthest Arctic regions. In nearly every instance the nests were placed in willows from two to five feet from the ground, and near water. In one instance Mr. Ross found the eggs of this species in the nest of _Turdus swainsoni_, which had either been deserted or the parent killed, as the eggs were in it, and would probably have been hatched by the Warbler with her own." As evidence of the late migration of this subspecies, Robie W. Tufts writes to me from Nova Scotia: "The latest date of departure which appears to be normal is October 7, 1936, though they generally leave during the second week of September. On November 25, 1929, a female was collected by me at Wolfville. The bird was searching for food very actively and its general behavior was decidedly abnormal. The bird's body showed slight traces of emaciation." Birds that have been recorded in Massachusetts as late as September 30, long after our local breeding birds have left, were probably of this subspecies. DENDROICA PETECHIA RUBIGINOSA (Pallas) ALASKA YELLOW WARBLER HABITS This subspecies was formerly supposed to range throughout most of Alaska, but its breeding range is now understood to be restricted to the coast region of southern Alaska and British Columbia, from Kodiak Island (the type locality) southward to Vancouver Island. It migrates through California to Mexico and Central America, and probably spends the winter in South America. In El Salvador, according to Dickey and van Rossem (1938), "this race was found only as a fairly common spring migrant through the upper levels of the Arid Lower Tropical. As with _D. p. aestiva_ the winter range undoubtedly lies farther to the south. It is notable that _rubiginosa_ occurs at somewhat higher elevation than the other three forms and was not found at all in the 'tierra caliente.'" This race has been reported in Kansas and in central Texas, but these birds may have been _amnicola_, which somewhat resembles _rubiginosa_ and which had not been accepted at that time. Ridgway (1902) describes the Alaska yellow warbler as "similar to _D. ae. aestiva_, but slightly smaller and much duller in color. Adult male darker and duller olive-green above, the pileum concolor with the back or else becoming slightly more yellowish on forehead (very rarely distinctly yellowish on forehead and fore part of crown); wing-edgings less conspicuous, mostly yellowish olive-green, sometimes inclining to yellow on greater coverts. Adult female darker and duller olive-greenish above, duller yellow below." He might have added that the chestnut streaks on the breast are narrower than in _aestiva_.