466 BIRDS OF AUSTRALIA. 



Its single white egg is about two inclies and seven-eightlis 

 long by nearly two inclies wide. 



There is no difference in the colouiing of the sexes, which 

 may be thus described : — 



The whole of the plumage chocolate-black; bill fleshy 

 white, the culmen and tips of the mandibles brown ; legs, 

 feet, and interdigital membranes yellowish flesh-colour. 



Total length 15 inches; biU If; wing 12; tail 5 ; tarsi 

 2 ; middle toe and nail 2^. 



Genus THIELLUS, Gloger. 



Bonaparte places in this genus the bird I have characterized 

 as Pifffinus spJienurus and the P. clilororliyncUm of Lesson. 

 These birds are slender in form and have long and pointed 

 tails. The former, if not both these birds, frequent the Aus- 

 tralian seas. 



Sp. 638. THIELLUS SPHENURUS, Gould. 



Wedge-tailed Petrel. 



Puffinus sphenurus, Gould in Ann. and Mag. of Nat. Hist., vol. xiii. 



p. 365. 

 Thiellus sphenurus, Bonap. Compt. Rend, de FAcad. Sci., torn. 1866. 



Puffinus sphenurus, Gould, Birds of Australia, foL, vol. vii. pi. 58. 



This species was procured by Gilbert on the Houtmann's 

 Abrolhos, off" the western coast of Australia ; he also observed 

 it on all the neighbouring sandy islands, but on none was it 

 more abundant than on West Wallaby Island, which appears 

 to be one of its chief breeding-places, and where it burrows 

 to a considerable distance before depositing its e^g. Mr. 

 Macgillivray also procured specimens of this bird on Lord 

 Howe's Island ; we may therefore infer that it frequents the 

 seas washing the whole of the southern portion of Australia. 



