IN TIMOR- LAUT. 361 



alhis ; Cauda nigra, rectricibus duabus externis albo terminatis ; rostro et 

 pedibus nigris: long, tota G'2, alee '6'7, caudce 3 '3. 

 Bab. Inss. Tenimberenses. 



06s. Afflnis L. atro-virenti et L. trkolori, sed superciliis curtis albis 

 dividenda. 



30. Aktamus leucogaster, Val. 



A. musscJienbroeki, Meyer, loc. sup. c.'t. 

 Hab. Larat, ins. Tenimberensem. 



Arfamus musschenbroehi, is the name proposed by Dr. Meyer for the 

 Timor-laut Wood-Swallow, which has been determined by Dr. Sclater as 

 A. leucogaster, Val. (P. Z. S. 1883, pp. 51 and 200). Of the Artamus from 

 Dr. Meyer's identical locality I have in my own collection three specimens. 

 I have examined carefully seventeen others from different localities, in the 

 very long series in the British Museum derived from Celebes, the Philip- 

 pines, Sumatra, Java, Lombock, Flores, Timor, Batjian, Buru, Halmalieira, 

 Goram, Aru, Batanta, and from N. Australia. The species in Ihe Dresden 

 Museum from the underlined localities are admitted by Dr. Meyer to 

 belong to A. leucogaster. It is impossible to separato my Timor-laut 

 skins from specimens collected in Zebu by the Ohallenger Expedition, 

 and determined by Lord Tweeddale (P. Z S., 1877, pp. 544-545). The 

 colour in both is absolutely the same. Lord Tweeddale, however, remarks 

 on the difference of dress — "one in which the upper plumage is of a 

 light bluish and cinereous colour, the other where it is of a more smoky 

 brown and bluish ash. This does not seem to depend on sex ; for one of 

 these examples (Zebu 3G2) is marked $ , while I possess a Luzon example 

 exactly similar, which Dr. Meyer determined to be a ? . The other Zebu 

 example (No. 370) is marked ? , and is in the paler bluish-grey attire." 

 I feel satisfied, after examinirg the specimens in the British Museum and 

 in my own collection, that the difference in coloration is one due to age, 

 for in young birds, the plumage is lighter than in the adult state. Dr. 

 Meyer's observation that the dark mantle reaches, in Timor-laut skins 

 only, just to the root of the tail, while in A. leucogaster it overlaps by 

 about a centimetre, is, in as far as the series referred to enables an opinion 

 to be formed, oae not sufficiently constant to support specific separation. 

 In several Timor-laut specimens examined, the dark plumage overlaps the 

 tail more than 1 centimetre, and even more than in others from different 

 parts of the Archipelago which have been hitherto recognised as A. 

 leucogaster. In skins of A. leucogaster from Mysol and Macassar, the 

 mantle is just conterminous with the root of the tail. Keally, however, 

 the absolute constancy of these measurements can be determined only with 

 accuracy in the flesh, for the way in which the skin is manipulated will 

 increase or diminish them by several centimetres. The same holds with 

 regard to another character given as differential — the greater amount, in 

 Timor-laut specimens, of white t)n the rump and upper tail-coverts. In 

 my own specimens the white on the rump varies from 22-31 millim. 

 in length, while in eight other skins from different regions of the 

 Archipelago the range is from 26-32 millim., giving in the latter indeed 

 a wider zone than in those from Timor-laut. In the long series of 

 British Museum skins, the vjhite tips of all but the two middle tail-feathers, 

 another of Dr. Meyer's differential characters, is quite inconstant. In 

 several Timor-laut skins not only these two tail feathers, but several 

 others of the remiges, are without a white band, while in some examples 

 it is even less than in undisputed A. leucogaster. In young birds the white 

 tips are very pronounced, not on the remiges only, but on the primaries 

 and secondaries of the wing also. The Philippine (Zebu) birds, already 



