CHARACTERS.--Similar to _O. xanthonotus xanthonotus_ Horsfield of Java, but larger with longer tail. Adult [Male] differing in color in much more heavily striped under parts and in the black of chest extending farther backward to include the upper breast; and much less sharply defined posteriorly against the white under parts; back more greenish yellow; yellow spot on outer tail feather large. The adult [Female] besides differing, as does the [Male], in heavier stripes below etc., has the whole pileum, occiput, upper neck, and sides of neck heavily streaked black and olive-green, and the throat and chest dull gray with whitish streaks. (A [Female] probably an older bird in the U. S. N. M. has the head neutral gray with an olive wash, very conspicuously streaked with black, the black streaks extending as in the others right to base of bill). MEASUREMENTS. EXPOSED NO. SEX LOCALITY WING TAIL TARSUS CULMEN 64,180 [Male] ad. Palawan: Puerto Princesa 121 78 21 23 33,225 [Male] ad. " " " 118 74 20 22 64,181 [Female] ad. " " " 110 69 21 21 64,179 [Female] ad. " Iwahig Penal Colony 109 68 21 21 REMARKS.--The Black-headed Oriole has been recorded from Palawan and Calamianes Islands only in the Philippines. The Palawan representative form is strongly marked and easily to be distinguished from _O. x. xanthonotus_ of Java. The bird of Borneo may represent still another form, distinguished from true _xanthonotus_ by slightly smaller size, the under parts less purely white, that is, much more suffused with yellowish or yellowish ochraceous, sometimes even with grayish and with the yellow tail-spots larger. This form probably should be known as _Oriolus xanthonotus consobrinus_ Wardlaw-Ramsay (P. Z. S., 1879, p. 709, N. E. Borneo). Everett, however, (Birds of Borneo 1889, p. 119), in mentioning the type states that "It is dissimilar from all known immature individuals of _O. xanthonotus_ and belongs rather to the _O. steerii_ group." If this is true and there is in north Borneo a form of the Philippine group of Orioles, with the sexes alike in plumage and with the throat and chest plain gray, then the form of the Black-headed Oriole of Borneo, if recognized, should be named. In old females from Java the pileum and cheeks are dark mouse-gray, blackish on the forehead, the black streaks narrow, almost obsolete and noticeable on the crown and occiput only. Females from the mainland and Borneo and Sumatra also, when adult, have faint blackish streaks on the crown. In immature plumage the head is wholly unstreaked, which I doubt to be the case in the Palawan form. The following Publications of the Museum of Comparative Zoology are in preparation:--