Report on the zoological collections made in the Indo-Pacific Ocean ...

16 COLLECTIONS FROM MELANESIA.a. Upper tail-coverts olive-yellow like the back ;outer aspect of secoadaries distinctly grey;pectoral collar joined to ear-covertsh. Upper tail-coverts black ;outer aspect of secondariesolive-yellow, with which they are marginedor washed externally.melarwra.. ohiensis.a'. Pectoral collar joined to ear-coverts clio.b'. Pectoral collar separated from ear-coverts.a". Upper surface olive-greenish ; wings externallywashed with greenish grey .... macrorhyncha.b". Upper surface golden olive ; wings externallywashed with the same colour .After having gone over the series in the British Museum, whichlikewise served as the basis of Dr. Gadow's studies, I regret that Imust entirely disagree with him. He appears to me to have arguedfrom immature specimens when he tries to show the variation ofthe species and attempts to prove that they run one into another.If it were possible to find in the same island examples of these Pachycephalcewith the black breast-band united to the ear-covertsand others with this disunited, all being fidly adult birds, then Dr.Gadow would have proved his point ; but this is exactly what doesnot take place, the difference in coloration being accompanied by adifferent habitat. It is not right to compare immature birds of oneform with adults of another, because in their young stages all thesespecies are unquestionably very difficult to distinguish apart ; but iffully adult birds are compared, I do not think there ought to beany difficulty in determining four distinct species.Again, with regard to his observations that the colouring of theupper tail-coverts " is of no specific importance," some attentionmust be given to the age and condition of the specimens. Inthe group with the upper tail-coverts black, it will be found thatthe basal ones are always more or less tipped with olive, and thatit is the long ones which are black. If, therefore, the latter areshot away, a superficial observer would jump at once to the conclusionthat the upper tail-coverts are olive-yellow. Even in this casethe yellow-washed quills (instead of grey) would enable one to distinguishthe P.-macrorhgncha group from P. mekmura. Then,again, it would appear from moulting specimens that the upper tailcovertswhen first grown have more olive-yellow on the marginsthan in the fully adult bird. Therefore in these Pach/ycephalce, asin other birds, only fully plumaged specimens should be compared,if one is to understand the relations of the various species.There can be no doubt that the locality " Celebes " attached tothe specimen from the Gould Collection is erroneous ; and Mr.Wallace has remarked on the absence of the genus in the aboveisland, in the essay quoted by Dr. Gadow.