155. RED-THROATED DIVER. _Colymbus septentrionalis_, Linnaeus. French, "Plongeon à gorge rouge," "Plongeon cat-marin."--The Red-throated Diver is a regular autumn and winter visitant to the Islands, and rather the most common of the three Divers. As with the Northern Diver, it occasionally remains until it has nearly assumed its full breeding-plumage, but it does not occur so frequently in that plumage as it does on the south coast of Devon and Dorset; indeed I have never found either this bird or the Great Northern Diver so common in the Channel Islands as they are about Exmouth and Teignmouth, even in the ordinary winter plumage; probably the mouths of rivers were more attractive to them as producing more food than the wild open seas of the Channel Islands. Owing to its various changes of plumage, from age or time of year, the Red-throated Diver has been made to do duty as more than one species, and is the Speckled Diver of Pennant, Montagu and Bewick. It is mentioned in Professor Ansted's list, but marked as only occurring in Guernsey. There is no specimen at present in the Museum. 156. GUILLEMOT. _Alca troile_, Linnaeus. French, "Guillemot à capuchon," "Guillemot troile."--The Guillemot is very common about the Channel Islands in Autumn and winter, but is seldom seen during the summer season except near its breeding stations, which, as far as my district is concerned, are very few. It does not breed in Guernsey, Sark, or Herm, or even on the rocky islands to the north of Herm. In Alderney, I am told, it has one small station on the mainland on the side nearest the French coast. I was told of this by the person who shot the Greenland Falcon, and by one or two of the fishermen on my last visit to that Island. I had not time then to visit the place, and on former visits I must quite have overlooked it. Captain Hubbach, however, kindly promised that he would visit the spot, and soon after I left, about the middle of June, 1878, he did so, and his account to me was as follows:--"I have been twice along the cliffs with my glass, but have not seen either a Guillemot or Razorbill. An old boatman here tells me that he took their eggs off the rocks at the French side of Alderney last year (1877), and that they bred there every year. He describes the eggs as 'the same blue and green and white ones with black spots that are on the Ortack Rock.'" This very much confirms what Mr. Gallienne says, in his notes to Professor Ansted's list--"The Razorbill and Guillemot breed on the Ortack Rock and on the cliffs at Alderney." This Ortack Rock is to the west of Alderney, between Burhou and the Caskets, and a considerable number of Guillemots and Razorbills breed there, but it is not to be compared as a breeding station for these birds with those at Lundy Island and South Wales. During the summer a few Guillemots, probably non-breeding birds, may be seen at sea round Guernsey, and one or two stragglers may generally be seen when crossing