260 WILSON'S STORM PETREL. 



To their breeding places they are migratory ; Mar- 

 tin writes, " It comes (to St. Kilda) about the 

 22d of March, without any regard to winds, lays 

 its eggs about the 20th of May, and produces the 

 fowl towards the middle of October, then goes away 

 about the end of November." 



The nest is placed among loose stones or rocks, 

 or in fissures, and a single pure white egg is laid ; it 

 remains concealed during the day, and appears at 

 dusk, which is the time of feeding and activity. 



A specimen before us has the upper plumage of a 

 dull black, the last feathers of the rump and the 

 base of the upper tail-covers pure white, forming a 

 broad band ; the tips of the greater covers are also 

 of a pale grey, marking their line across ; the un- 

 der parts are brownish black or pitch-brown with a 

 white patch behind each thigh ; legs, feet, and bill 

 black. We are not aware that there is any dif- 

 ference in the sexes.* 



WILSON'S STORM PETREL, THALASSIDROMA WIL- 

 SONII. This bird was given by Mr. Jenyns as an 

 accession to the British List, in " Vertebrata," on 

 the authority of birds procured, or thought to be 

 procured, in the British Channel ; but since that, 

 Mr. Yarrell, in the concluding parts of his excellent 

 British Ornithology, from which we have derived 

 so much advantage in the progress of these volumes, 

 nas recorded four specimens picked up in Cornwall, 

 * The tail, in the Plate, is represented too much rounded. 



