454 THALASSIDROMA LEACHII. 



on account of the shortness of its legs, although it frequently 

 allows them to hang down. In this it resembles Thalassi- 

 droma pelagica, and Wilson's Petrel has a similar habit 

 during calm weather. I have seen all the three species 

 immerse their heads into the water, to seize their food, and 

 sometimes keep it longer under than I had expected. About 

 the 1st of June the species collect in numbers, and return to 

 their breeding-places. They now fly in front of the high 

 rocks, passing and repassing a thousand times in the day, 

 enter their dark and narrow mansions, or stand in the passage, 

 and emit their cries. Now they alight on some broad shelf, 

 and walk as if about to fall down, but with considerable ease, 

 and at times w'ith rapidity. Now and then the mated birds 

 approach each other, and, I believe, disgorge some food into 

 each other's mouths. They collect grass and pebbles, of 

 which they form a flat nest, on which a single white egg is 

 deposited, which measures an inch and a quarter in length, 

 by seven-eighths in breadth, is nearly equally rounded at 

 both ends, and looks very large for the size of the bird. When 

 boiled it has a musky smell, but is palatable. When you 

 pass close to the rocks in which they are, you easily hear 

 their shrill querulous notes ; but the report of a gun silences 

 them at once, and induces those on the ledges to betake 

 themselves to their holes." 



Like some of our other species, this has repeatedly been 

 found dead, or in an exhausted state, near the coast, and even 

 far inland, during or after stormy weather in winter. Many 

 instances of its occurrence in various parts of Ireland arc 

 mentioned by Mr. Thompson. 



Remarks. — Although discovered by Mr. Bullock, -who, it 

 appears, knew it to be a distinct species, it was first described 

 by M. Temminck, who dedicated it to Dr. Leach, of the 

 British Museum. Dr. Fleming afterwards named it Procel- 

 laria Bullockii, in honour of its discoverer, and " in order to 

 do an act of common justice to the individual who had energy 

 to undertake a voyage of inquiry, and sagacity to distinguish 

 the bird in question as an undescribed species." Mr. Selby 

 has followed Dr. Fleming in this matter, while others retain 



