1872.] ON THE BIEDS OF CELEBES. 163 



I have compared two Macassar male examples collected by Mr. Wallace with a large series Tr. Z. S. vm. 

 of Javan individuals, and have failed in detecting any valid specific differences. The black-naped 

 Orioles, before attaining their full plumage, ])ass through a stage wherein the two centre rectrices 

 retain the olive-green hue found in younger birds, while they have already put on the black 

 feathers which surround the head, and the full bright adult yellow plumage of the entire under 

 surface, the crown, the neck, and the rump, the plumage of the back alone showing immaturity 

 by traces, more or less, of dingy greenish-yellow. It would seem that the central pair of olive- 

 coloured rectrices are not moulted and replaced by a pair of new black feathers, but rather that 

 the olive-green hue changes gradually into black, commencing from near the tips, which are pure 

 yellow at the earliest stage, and thence passing upwards. In adult Javan examples the lesser 

 wing-coverts are tipped with yellow, thus forming a conspicuous yellow speculum. But in Javan 

 examples in the stage of plumage above described, these yellow tips are frequently absent, or only 

 commencing to be developed. The two Macassar examples are in the intermediate stage of 

 plumage described above : the one has no yellow tips to the lesser wing-coverts ; in the other 

 they are just appearing. Whether in perfect plumage the yellow alar bar is wanting, as in the 

 Sula B. frontalis, has yet to be ascertained. In the mean time I shall retain the Macassar Oriole 

 under the title of the Javan bird. The Macassar species is somewhat larger. Wing 5f , tail 4f , 

 bill |. 



The only Menado example I have been able to examine is in the intermediate stage of 

 plumage, with green middle rectrices and no alar bar. It differs in that the black coronal ring 

 does not unite at the nape, the yellow of the crown being thus confluent with that of the nape. 

 As indications of the complete black circle in Broderiims appear in the earliest stages of plumage, 

 this break in the coronal ring cannot be a sign of nonage. The dimensions differ from those of 

 the southern form. Wing 5|, tail 4|, bill |. It possibly represents a distinct species. 



TURDID^. 



Geocichla, Kuhl. 



67. Geocichla erythronota, Sclater, Ibis, i. p. 113, " Macassar " (1859). (PI. VI. fig. 2, 

 in orig.) 



Hah. Macassar {Wallace). 



This species and G. interpres (Kuhl) form a section of the genus which perhaps deserves a 

 subgeneric title. 



Tunlus avensis, J. E. Gray, Griffith, Anim. Kingd. Birds, i. p. 530, pi. — , named from an 

 Indian drawing, is either G. interpres or else an unknown Burmese representative form. 



TIMALIID.E. 



Trichostoma, Blyth. 



68. Trichostoma celebense, Stricldand, Contr. Ornith. 1849, p. 128, pi. — , "Celebes." 

 Ilab. Macassar {Wallace). 



Tr.Z.S.viii. 

 p. G2. 



