PUFFINUS CUNEATUS. 



phase of plumage, such as is found in several other species of Petrels. Mr. Anthony 

 undoubtedly proved this to be the case with P. cuneatus, as he met with both light 

 and dark-breasted birds on San Benedicto, where, however, the darker form was in 

 the proportion of two to one. 



Mr. Anthony says that, in a series of about seventy-five specimens, all manner 

 of intergrades could be found, from those with pure white lower parts, including the 

 under wing-coverts, to those having grey and sooty-brown plumages. 



It should be noticed that the colour of the axillaries follows, to a great extent, 

 the phase of plumage. Thus, the grey-breasted birds have greyish-brown axillaries, 

 with a little white near the tip, whereas the white-breasted birds have ashy-coloured 

 axillaries, but with much more white mottling towards the end of the feathers. The 

 whiter the under-surface of the bird, the greater the amount of white on the axillaries. 



All but one of the Laysan examples in the Rothschild Collection are of the white- 

 breasted form, but a grey-breasted bird was found by Palmer on French Frigate 

 Island, along with a white-breasted one. From San Benedicto I have examined seven 

 specimens obtained by Mr. A. W. Anthony. Five of these are sooty-brown below, 

 but the other two are white underneath, one having the sides of the body grey, and the 

 other being slightly washed with ashy-grey. In both phases the axillaries are for 

 the most part grey. 



The size, as in other Shearwaters, varies considerably, the following being the 

 measurements of the series examined by me : — 



c? Wing, 11.1-12.0 inches; culmen, 1.45-1.6; tarsus, 1.8-2.0; middle toe and 

 claw, 2.1-2.3. 



? Wing, 11.3-12.0 inches; culmen, 1.4-1.6; tarsus, 1.8-2.0; middle toe and 

 claw, 2.1-2.25. 



Specimens without indication of sex measure : — Wing, 11.2-11.85 inches ; culmen, 

 1.55-1.65 ; tarsus, 1.8-1.95 ; middle toe and claw, 2.2-2.4. 



It will thus be seen that there is practically no difference in size between the male 

 and female. 



The white breast which Salvin considered to be a distinctive character of his 

 P. cuneatus is discounted by the discovery of a grey-breasted phase, and in this plumage 

 it is exceedingly difficult to separate the dark form of P. cuneatus from P. chlororhynchus. 

 The bill of the latter bird is generally smaller, and it has not such a grey throat. The 

 two birds are, however, scarcely distinguishable, and if it should turn out that the dark 

 phase of P. cuneatus is not different from P. chlororhynchus, we should be confronted 

 with the fact that P. chlororhynchus ranges from the Australian seas to the Mascarene 

 Islands, and re-appears in the Japanese seas, extending to the Californian Islands and 

 the Hawaiian Archipelago. In Japan and the other localities to the south, there is a 

 white-breasted phase, which is not found in Australian and Mascarene specimens, 

 which are always dark. I would, however, call attention to the Plate in the 7th 



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