495 



or gliding at intervals, and then plying their feathery oars. It is only when picking up their 

 food that, with upraised wings, they hover over the spot, and pat the water with their feet, 

 although many persons have described this as their ordinary mode of progression. In calm 

 weather, when the sea is smooth, they hover, skim, and wheel around, much in the manner of 

 Swallows, though with less velocity." 



During the breeding-season the Storm-Petrels are found on the islands which they have 

 selected for the purposes of nidification, and appear to remain during the daytime quietly in 

 their holes, issuing forth in great numbers at night and wandering out to sea. They nest 

 amongst the stones or in holes in the cliffs, their nest being merely a collection of small pieces 

 of the stalks of plants placed in a depression in the ground ; and one egg only is deposited. 

 Mr. Robert Gray says that in the Island of Soay, near Iona, they have their holes in soft mud, 

 the entrance-halls of which are about as large as rabbit-burrows. From these other smaller 

 galleries branch off, so that one external aperture serves as a kind of lobby for a number of 

 pairs. When in their holes they utter a chattering sound, which Mr. Hewitson compares to 

 the warbling chatter of the Swallows when fluttering above the chimneys, which sound guides 

 an intruder with tolerable facility to their retreat; but they frequently nest under such large 

 boulders that they are safe from intrusion. 



Of the eggs of the present species I have a few series from the Fseroes and the islands of 

 the Scotch coast, which in size average 1^- by |-g- inch, are oval, rather elongated in shape, pure 

 white in colour, having a chalky surface to the shell, and some have a small zone of pale reddish 

 dots round one end. 



The specimen figured, on the same Plate with Leach's Petrel, is an adult male from the 

 Orkneys, in my own collection, and is the bird described. 



In the preparation of the above article I have examined the following specimens : — 



E Mus. H. E. Dresser, 

 a, 6 . Orkneys {Dunn), b, c,6 . Filfla, Malta, June 5th, 1874 (C. A. W.). c,pull. Orkney (Dunn). 



E Mus. E. Hargitt. 

 a, 6. Shetland (Dunn), b. Havre, November 15th, 1872. c, pullus. Orkney, August 3rd, 1869 (Dunn). 



E Mus. C. A. Wright. 

 a. Filfla, Malta, May. b, c, d,e,6. Filfla, Malta, June 5th, 1874 (C. A. W). 



