436 Mr. E. V. Harcourt on the Ornithology of Madeira. 



Manks Shearwater with which it is sometimes confounded, is 

 salted by the natives and considered eatable. 



The Manks Shearwater [Puffinus Anglorum, Ray) is also very 

 common. 



The Dusky Petrel {Puffimcs obscurtis, Temm.), another inha- 

 bitant of the Dezertas, may be easily distinguished from the fore- 

 going species, which it strongly resembles, by its inferior size as 

 well as by the colour of its feet. The Anglorum has the feet of 

 a flesh-colour, whereas in obscurus they are of a bluish ash- 

 colour. Anglorum has likewise all the secretions yellow, but in 

 the case of obscurus they are of a dark green colour. Both 

 Anglorum and obscurus may be easily tamed, and will live upon 

 almost anything. They run along the ground on their bellies, 

 and use their curiously-shaped bills in climbing up the rocks. 

 Their habits are crepuscular, and in the daytime they hide 

 themselves in any holes or crannies within their reach. 



Bulwer^s Petrel [Thalassidroma Bulwerii, Gould) has been 

 described by Sir W. Jardine*, who says, "it is easily distinguished 

 from any other by having the two centre tail-feathers elongated, 

 as in the genus Lestris, and not even or forked like the other 

 Petrels." This Petrel is identical with that described by Dr. 

 Heneiken under the title of Procellaria anginho ; and has also 

 been called Puffinus columbinus by Webb and Berthelot in their 

 work on the Canary Islands. Dr. Heineken describes it as having 

 no white about the rump or flanks, and as ha\ing the tail slightly 

 forked. j\Ir. Yarrell has justly observed, that the squareness or 

 forkedness of the tail in Petrels is an unfair criterion of spe- 

 cies, as this property in a very gi*eat measure depends upon the 

 age of the individual, and varies accordingly. The plumage of 

 this Petrel is entirely uniform brownish-black, and it is very 

 common on the Dezerta Islands. 



The Forked-tailed Petrel {Thalassidroma Leachii, Temm.) is 

 also found on the Dezertas. This bird was describedf under 

 the title of Thalassidroma Castro X, from a supposed difference 

 which appeared to exist between the measurements of specimens 

 from Madeira and those from other parts. Specimens from 

 Madeira seemed to exhibit shorter w4ngs and shorter tarsi, though 

 the entire length of the birds was greater. The tails also of the 

 Madeiran birds appeared to be square instead of forked. This 

 latter characteristic, as has before been observed, forms no safe 

 criterion ; and Forked-tailed is not quite so distinctive an appel- 

 lation for the species as might be desired. 



* Ilhistrations of Onijtbology, by Jard. & Selb. ; and Edinb. Joiu'n. of 

 Nat. and Geog. Science, Jan. 1830, p. 245. 



t "Sketch of Madeira," Murray, 1851, p. 123. 

 X Roque de Castro is the local name of this bird. 



