MONOGRAPH OF THE PETRELS. 



collar on the fore-neck, some of the birds having this band very distinct, while in others 

 it is all but absent. One specimen in the British Museum is totally grey underneath, 

 excepting for a little white on the throat (spec, k of the Catalogue of Birds) : this is the 

 dark phase of the species. Another bird (spec, n of the Catalogue of Birds) is entirely 

 white on the under-surface from the chin to the under tail-coverts, and between 

 this and the grey phase exists every variation in the amount of grey mottling on the 

 fore-neck, the chest, and sides of the body. 



The description is taken from a female bird in typical plumage from Lat. 37° 14' 

 S., Long. 10° 5' W., in the Rothschild Collection. The specimen figured is from the 

 South Atlantic Ocean (spec, a of the Catalogue of Birds) from our collection. 



200 



