PACHYPTILA FORSTERI, Stephens. 

 Forster s Prion. 



PLATE XLVII. 



P. coerulescente-grisea, subtus alba, remigibus rectricumque apicibus nigris, rectrici- 

 bus duobus mediis longissimis. 



Procellaria vittata, Gmel. Linn. vol. ii. p. 560. 



Procellaria Forsteri, Lath. Ind. Orn. vol. iii. p. 827- 



Pachyptila Forsteri, Steph. in Shaw's. Gen. Zool. vol. xiii. p. 251, 



W e have figured and described this bird from a specimen lent to us 

 by the Zoological Society of London, under the above title, with a degree 

 of doubt, being unable to procure the Voyages of Forster, where a de- 

 scription of the Vittated Petrel is given, and which synonym is quoted by 

 Latham under his Procellaria, and by Stephens under his Pachyptila 

 Forsteri, the species with which our specimen most nearly agrees. There 

 appears another, the P. ccerulea, which, if not the same, approaches very 

 near to this. The description of both are by most authors copied from 

 Forster, and without any attempt to clear up the distinction between them. 

 In this genus, the changes of plumage undergone at different ages, seem 

 to be under the same regulations as among the Gulls and Petrels ; and 

 the brownish colour of the plumage of some, with the dark centres of the 

 feathers, indicate immature plumage, rather than a decided distinction of 

 species. 



The Prions were originally placed among the Petrels, next to which 

 they should stand ; but they differ from them, in the broad and dilated 

 bill, and in having the edges of this member very distinctly pectinated, as 

 in the genus Rynchops among the Anatidce. This formation, including 

 some minor modifications in their form and plumage, beautifully connects 

 the family, the first in the order of Natatores, with the other extremity of 

 the circle, ending with the Laridts, and to the more typical families of 

 which they are again joined by means of the true Petrels, Fulmars, &c. 



