B76 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



regularity about the middle of April ; at first, like the 

 Guillemots, they only stay for three days and then go 

 to sea again for another three days, but they gradually 

 stay later. Though they arrive later than the Guillemots, 

 they begin to lay earlier, and by the end of the first week 

 in May a large number of birds have laid. On rune 

 10th I found that they were just beginning to hatch out. 

 They begin to leave about the middle of August, and 

 by the end of that month nearly all the birds have dis- 

 appeared, and they are not seen again until the following 

 April. 



Procellaria felagica (The Storm-Petrel). 



Plentiful on Soay, but it appears to be scarce on the 

 other islands; though it probably breeds in other locali- 

 ties, the eggs have not, so far as I know, been taken 

 elsewhere than on Soay. On the occasion of my visit 

 to the latter island I was too early for this bird, and I 

 was unable to land there later owing to the stormy weather. 

 I have, however, seen eggs which were taken there sub- 

 sequent to my visit, on ground which I had traversed. 



Oeeanodroma leueorrhoa (Leach's Fork-tailed Petrel). 



St. Hilda is the great head-quarters of this bird in the 

 British islands, and it is still plentiful there in spite of 

 the serious inroads made upon it by the natives in order 

 to supply the demands of dealers and tourists. I cal- 

 culated that between 300 and 400 eggs were taken by the 

 natives for this purpose last season. It is most abundant 

 on Boreray, but it also breeds plentifully on Soay, whilst 

 it is fairly frequent on Dun, though much less plentiful 

 there than formerly owing to the manner in which it has 

 been harried. It also breeds sparingly on the main 

 island, and, as before mentioned, I discovered a small 

 colony breeding on Levenish. It especially frequents 



