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Sept, 1914 STATUS OF CERTAIN ISLAND FORMS OF $.4LPINCTES 213 though at least one writer (Willett, 1912, p. 101) has questioned its distinct- ness, it has received quite general recognition as a valid race. The subspecies was described from very worn adults, collected in May, no birds in fresh autumnal plumage being available. This want has now been filled by the loan of four September specimens from the Thayer collection, and I have consequently been able to make more satisfactory comparisons of island and mainland birds than has been done heretofore. The characters of $. o. pulverius as given by Grinnell (1. c.), consist, as compared with $. o. obsoletus, of notably greater size of bill and feet, and peculiarly yellowish coloration; as given by Ridgway (1904, p. 649), o ? "larger and relatively stouter bill and much paler, more buffy coloration." First, as regards the supposed color differences: Grinnell (1. c.) remarks that the "yellowish coloration may be due in part to the bleaching and abrasion of the plumage, but the character is, nevertheless, quite apparent when compared with mainland specimens in correspondingly/worn plumage." The ochraceous suffusion remarked upon is truly a conspicuous feature of San Nicolas Island birds in abraded summer plumage, and it is not apparent in any similarly worn examples from the neighboring mainland, but nevertheless it is merely an adventitidus acquisition, and one that can not be regarded as a specific character. This despite the fact that it could probably be safely used in distinguishing midsummer birds! In a similar manner four of the five adults of guadeloupensis at hand, collected in May, are more or less discol- ored with a reddish suffusion over the entire plumage. This also, it is safe to say, is the resuit of some peculiarity in surroundings acting directly upon the feathers, and not to be considered as an inherent character of the species. Four September specimens and one January bird from San Nicolas ]'sland have been carefully compared with corresponding mainland spe- cimens, and I am unable to distinguish the slightest significant difference in color or pattern. Shade and markings of back, breast, flanks, under tail coverts, etc., have been considered separately, and while there is great varia- tion in all these features among birds from any region, I can find no tendency among the San Nicolas Island specimens toward the development of any distinctive color character. Second, as regards differences of size: As shown in the accompanying table of measurements, $. o. pulverius as compared with the mainland $. o. obsoletus, has a slightly greater average length of culmen. This difference in culmen length is, I believe, somewhat greater than appears in these tables, especially as regards the females, where, according to the figures, it is not very well marked. Of the six females used iu the measurements, four were collected in September. They are in fresh winter plumage, but whether they are adults, a year or more old, or iramatures of the previous spring, was not noted by the collector, and there is not now, of course, any way of telling. To ascertain something of the variation by age I measured a small series of mainland birds in first winter plumage, the age determined by condition of the skull, and found the length of culmen appreciably less than in others unquestionably adult. In September collecting msny more iramatures than adults are taken, and it may well be that most or all of the San Nicolas Island September birds at hand are immatures in first winter plumage. Thus, invaluable as they are for color comparisons, it is possible that these specimens are not to be relied upon to show the true chsracter of the race as regards length of