PROCELLARIA 
Cook’s 
CO OKU, 
Petrel. 
G. R. Gray. 
Procellaria CooJcii, G. R. Gray in Dieffenbach’s Trav. in New Zealand, vol. ii. p. 199— List of Birds in Brit. Mus. 
Coll., Part III. p. 165. 
— velox, Sol. MSS. Banks’s Icon, inedit. t. 16? 
leucoptera, Gould in Proc. of Zool. Soc., Part XII. p. 57 ; Ann. and Mag. of Nat. Hist., vol. xiii. p. 364. 
I have been informed that this species breeds in abundance on one of the small islands near the mouth of 
the harbour of Port Stephen, in New South Wales, where my specimens were procured. I frequently saw 
it during my passage from Sydney to Cape Horn, but it was most numerous between the coast of Australia 
and the northern part of New Zealand. For a true Petrel it is one of the most elegantly formed species of 
the genus, and is rendered conspicuously different from the rest of its congeners by its white abdomen and 
under wing-coverts, which show very conspicuously when the bird is on the wing, particularly when seen 
from beneath, as it frequently may be when the breeze is fresh or a gale rising ; it seldom, however, even 
then mounts higher than the vane of the vessel. 
From the number of species figured in the present work, it will be seen that the Australian seas abound 
with Petrels, the investigation of the various species of which, their habits and economy, as well as their 
places of abode, will serve to occupy the attention of ornithologists for years to come. It could scarcely be 
expected that a single voyage to Australia could add much to our knowledge of the subject ; my readers 
must therefore be contented in this instance with little more than an illustration. That, like the other 
members of the genus, it subsists upon small fishes, medusae, and others of the lower marine animals, there 
can be no doubt. 
The sexes do not differ in external appearance. 
Crown of the head, all the upper surface and wings dark slaty black ; tail slate-grey ; greater wing- 
coverts slightly fringed with white ; face, throat, all the under surface, the base of the inner webs of the 
primaries and secondaries, and a line along the inner edge of the shoulder pure white ; bill black ; tarsus 
and basal half of the interdigital membrane fleshy white ; remainder of the toes and interdigital membrane 
black. 
The Plate represents a male and a female of the size of life. 
