_Eggs._--Three eggs seems to form the usual set for the mangrove warbler; in the Thayer series there are five sets of three and one set of two. Ed. N. Harrison (MS.) says that "it seems that one egg is a set as often as two." Most of the eggs in this series are ovate, but some are short ovate; they have only a very slight gloss. They are white or creamy white, speckled, spotted or blotched with shades of "mummy brown," "bone brown," "Prout's brown," or "clove brown," with undertones of "light mouse gray," "deep mouse gray," "Quaker drab," or "drab-gray." The browns are frequently so dark as to appear almost black, but some eggs are spotted with lighter shades, such as "cinnamon brown" and "snuff brown." On the more lightly marked types the most prominent markings are the grays, with only a few scattered brown spots. Often a loose wreath is formed around the large end, where the spots are usually concentrated. The measurements of 32 eggs average 17.9 by 13.4 millimeters; the eggs showing the four extremes measure =19.5= by 13.2, 17.9 by =14.6=, =17.0= by 13.2, and 18.3 by =12.9= millimeters (Harris). _Plumages._--Although I have examined a large series of mangrove warblers, I have seen no downy young and no summer birds in juvenal plumage. But Dr. Chapman (1907) describes the young female as "above grayish olive-green, rump brighter; tail blackish, externally greenish, webs of all but central narrowly margined with yellow; wings and their coverts blackish, quills margined, coverts tipped with dull greenish; below whitish more or less washed or obscurely streaked with yellow, the under tail-coverts pale yellow." Young males in the fall are much like adult females, but brighter in color and often with traces of chestnut on the head. Apparently young males wear this femalelike plumage all winter; young males in March show a variable amount of chestnut on the head and throat, and show further progress toward maturity during April, May, and June, indicating a first prenuptial molt. A specimen described by Brewster (1902) is apparently undergoing this molt. "It has the head dull chestnut, very pale and mixed with whitish on the throat, mottled with greenish on the crown; the jugulum, sides of the neck and the middle of the breast _white_ with occasional small patches or single feathers of a pale yellow color and numerous fine, chestnut-rufous streaks on the breast; the remainder of the under parts pale primrose yellow mixed with whitish. The back, wings, and tail are nearly as in the adult female. The upper mandible is of the usual dusky horn color, but the basal half of the lower mandible of a pale flesh color. The plumage, generally, has a worn and faded appearance."