BIRDS OF LLEYN, WEST CARNARVONSHIRE. 505 



times. With the aid of the glass, I made out (judging from the 

 birds on the sea) that there was about one Razorbill (easily dis- 

 tinguished by its neater shape, head drawn back and tail raised, 

 from the paler and browner Guillemots) to every six or eight of 

 the latter birds. A few Razorbills breed on St. Tudwai's, and at 

 the date of my visit were sitting on eggs in shallow cracks and 

 covered ledges for the most part, but one or two were on open 

 ledges. They all occupied detached places, and did not sit two 

 or three close together like Guillemots. In every case but one 

 the birds sat or lay on the eggs in a semi-horizontal position ; 

 the exception was half upright, but, as I could see its eggs, it was 

 probably alarmed. When sufficiently alarmed they shuffled their 

 eggs from under them, stood up, and dropped off the ledges. As 

 Mr. Coward found Razorbills plentiful at sea near Nevin, they 

 probably breed on the north coast also. As to the Manx Shear- 

 water, I am unable to add anything of importance to what Mr. 

 Coward has already recorded in ' The Zoologist.' There is, 

 however, no doubt that " Mackerel Cocks " breed on the main- 

 land, and some of the islands of western Lleyn. This is not 

 surprising when we remember that a great breeding haunt of this 

 species lies off the southern horn of Cardigan Bay. I saw remains 

 of two or three dead birds, and when off in a boat one morning 

 saw five skimming low over a rather lively sea ; but they are 

 chiefly nocturnal. They strike the light sometimes, and flutter 

 down into the court. They are very stupid, and make no attempt 

 to escape, but fly away when thrown up into the air. I was told 

 that when the Mackerel come into one of the bays in July and 

 August lots of Shearwaters were seen over the shoals. 



I have only to add that this paper applies to the western part 

 of the Carnarvon promontory, and that it is offered as a small 

 instalment towards the history of the Birds of North Wales. 

 During the spring of 1900 I hope to continue my observations. 



Zool. 4th ser. vol. IV., Nove?nber, 1900. 2 M 



