THE BIRDS OF AUSTRALIA. 
this and the Monterey bird I called P, couesi, so that it is conclusively clear 
that no reliance can possibly be placed upon written accounts of these birds 
and not too much upon the results of criticism of few specimens. 
Having reached this conclusion, it is necessary to record that Loomis 
rejects my name for the present species, maintaining Forster’s name of 
Puffinus gavia, stating that “in some specimens the sooty black of the 
upper parts has a bluish cast in certain lights,” and then adds a note 
regarding Hull’s Cinathisma cyaneoleuca, concluding : “ Mr. Mathew’s con- 
tention respecting the identity of Procellaria gavia J. R. Forster wholly 
breaks down, the species having a brown as well as a bluish phase.” 
Loomis then lumps all the obscurus-assimilis group as referable to one 
species, the two I separated being regarded as colour phases, writing : 
“ I have grouped under Puffinus ohscurus several book species, beUeving 
them to be merely variations of a single widely distributed and essentially 
non-migratory species. The material before me confirms that the inter- 
gradation is complete between the brownish-backed and bluish-backed 
birds, and that they are not separable as distinct species. Perhaps the 
explanation of the dual coloration is to be found in dichromatism, more 
or less modified by geographic variation.” Then Loomis does not cata- 
logue any save Galapagos birds, so we are left in doubt as to whether 
he has studied the matter he dismisses so lightly. It is quite certain, 
however, that much more and better work must be done in connection 
with these Petrels before we can consider the matter in a dogmatic 
fashion. I endeavoured to deal with the matter without prejudice and 
with much study, and have since reconsidered the items as new material 
has become available, and will do so again without any consideration 
save the arrival at the truth. Thus, while disagreeing with Loomis’ 
treatment 1 appreciate his remarks in connection with the present species, 
and wiU certainly attempt a revision when topotypical series are at hand.. 
With regard to the ohscurus-assimilis association, I can only maintain 
the conclusions I arrived at until we have more knowledge on the subject. 
It is noteworthy that the notes on the Galapagos birds referred to, 
P. dbscuTUS, state: “The flight is usually low and somewhat undulatory, 
ascendant during the rapid wing-strokes (which vary from four or five 
to eight or ten) and descendant during the short sail.” 
This suggests the flight of the present species, on account of which 
Hull named it the “ Fluttering Petrel.” 
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