NOVITATES ZOOLOOIOAE XXVI. 1919. 133 



55. Dicrorns (bracteatus ?) buruensis Hart., subsp. nov. 



This very distinct form differs from D, amhoinensis, with which it lias 

 hitherto been united, by its considerably larger dimensions. While in D. (brac- 

 teatus ?) amhoinensis the wmg in males measures to about 150, in females to 

 140 or less, the wings in burnensis measure in males about 155, females about 

 145. The tail in ainhoinensis does not exceed about 146 or 147, in Buru speci- 

 mens it measures 166 — 178 mm. in males. 



Type : cJ ad., " Mt. Madang," West Buru, 6. iii. 1902. Heinrich Kiihn leg. 

 No. 4712. 



ORIOLIDAi:. 



56. Oiiolus flnschi Hart. = Oriolus striatus finschi. 

 Oriolua finacU Hartert, Nov. Zool. 1904, p. 219 (Wetter). 



Type: <J Wetter (Wetar) Island, north of Timor, 16. iv. 1901. Heinrich 

 Kiihn leg. No. 5604a. 



I have decided to treat Oriolus finschi, as well as bouruensis, decipiens and 

 even viridijuscus, as subspecies of striatus. The latter is, in my opinion, the 

 most primitive of these forms, in which the sexes are still similar and heavily 

 striped, while the striping becomes more indistinct in the other forms, and the 

 sexes in finschi are ah-eady a little different, while they have reached the greatest 

 divergence in viridijuscus, the male of which, with its green head and back and 

 ashy throat and chest, seems to be quite different, while female and young are 

 quite similar to finschi. 



In a most interesting discourse in Novitates Zoologicae, 1914, pp. 395- 

 400, Stresemann has discussed the origin of the well-knowTi similarity between 

 Orioles and Honey-eaters on Buru, Ceram, and other islands, and discredited 

 the recently quite popular theory of mimicry in these cases, explaining the 

 interesting phenomenon by an independent similarity of their course of develop- 

 ment. I follow these clever deductions with great interest, and 1 quite see, 

 and always felt, the weakness of the theory of mimicry in this case, because 

 there seemed to be no particular need for this extraordinary mimicry, and the 

 Honey-eater is no more able to withstand the attack of a hawk than the Oriole. 

 There is, however, one remarkable fact which requires some more explanation, and 

 which has not been mentioned by Stresemann : On the Timorlaut (Tenimbcr) 

 Islands the Philemon moluccensis timorlaoensis not onlj' resembles Oriolus striatus 

 decipiens so closely in coloration, as to make their similarity really deceptive, but 

 the Oriole has the feathers of the hind-neck also ruffled and defective, as is the 

 case in the Philemoii. It is perfectly true, that Wallace's statement that the 

 Buru-Oriole has an incipient knob at the base of the culmen is imagination, 

 and the same is, according to Stresemann, who has observed both birds in their 

 native home, the case with the supposed mimicry of voice and flight, but the 

 curious " defective " character of the neck-feathers, well known in the Phile- 

 mon, where they are often quite curly, is an evident fact in Oriolus s. decipiens 

 and also sometimes noticeable, at least during moult, in Oriolus s. bouruensis. 

 The reason for this cannot in my opinion be the moult alone, or if it should 

 be, it would be just as curious, as in other birds the hind neck-feathers do not 

 moult in this way, all at once, so as to produce the appearance of a Philemon- 

 neck. 



