^°m-?"] KI.\(;il()RX eV- C.\\\.E\, Sionu Petrels. 87 



or contracted in a made-ui) skin, so a considerable allowance 

 must be made in com])aring sucli measurements. 



The skins before us, when measured from the forehead to the 

 tip of the tail, vary from 170 mm. to 179 mm., while the 

 measurements given by Mathews^^ of his nominal species vary 

 from 200 to 215 mm. If, however, our si)ecimens be measured 

 from the tip of the bill to the tip of the tail, the measurements 

 exceed 200 mm., and almost correspond with those given by 

 Mathews. 



Colour. — Having disposed of the measurements, we will pro- 

 ceed to deal in detail with the arrangement of the colours in 

 the three specimens before us, com])aring them with those given 

 in Mathews' descriptions. The followmg is his descri])tion of 

 F. royanus: "Entire plumage sooty black, darkest on the upper 

 tail coverts. Wings and tail black. A large subterminal band 

 of white is noticeable on the under surface and the upper tail 

 coverts, on examining the feathers. Tail square." The speci- 

 men collected by McCuUoch and Troughton at Erskine Valley 

 (A) agrees better with this description than with that of any 

 other of the nominal species, but the abdominal and lower breast 

 feathers are, here and there, white almost to their tips, which 

 gives a mottled ai)pearance to these parts. The upper tail coverts 

 also show a little white, and we regard this bird as in a more 

 advanced stage of moult than F. royanus, and think that several 

 more moults would leave the abdomen pure white, as in F. gral- 

 larhis. Further evidence in support of this contention is 

 afforded by the characters of .specimen (C). The colour de- 

 scription, as published by Mathews,!^ is reprinted here: "It is 

 much darker than F. g. yrallaria, and has black fringes to the 

 rump feathers, square tail, the bases of the feathers of the 

 throat are dark, but the white lower-breast and abdomen are 

 flecked with grey, especially noticeable on the flanks, and the 

 axillaries are streaked ivith grey, whereas in every other speci- 

 men they are pure white ; the under tail-coverts are white with 

 dark tips, whereas in F. g. grallaria they would be said to be 

 dark with white bases." We cannot find much difference in 

 these two last statements ; examination of the specimen shows 

 that some of the under tail coverts are largely white with dark 

 tips, and others largely dark with white bases. "Another 

 noticeable feature is the lack of white on the inner wing coverts." 

 The specimen (B) presented to the Australian Museum by Mr. 

 Baxter has more white than that collected by Messrs. McCulloch 

 and Troughton (A), but a little less than the example described 

 by Mathews (C). It shows just a little white on the under sur- 

 face of the wing. 



With the exception of Vieillot's type, all the specimens on 

 which the various names are based are from Lord Howe Island. 

 Vieillot's bird was taken in southern seas, on the voyage to Aus- 

 tralia, and he states definitely that it came from Australia when 

 he writes "on le trouve a la Xouvelle Hollande." 



