30 ANNALS OF SCOTTISH NATURAL HISTORY 



LESSER BLACKBACK GULL, Lants fuscus. A summer visitor in 



June, July, and August. 

 GREAT BLACKBACKED GULL, Larus marinus.-T\vo or three are 



constantly here. 

 GLACOUS GULL, Larus glaucus. One or two immature birds 



periodically seen in November, December, and January. The 



latest occurrence was on 3rd April 1904. 

 KITTIWAKE, Rissa tridactyla. A few may be termed resident all the 



year round ; but in August especially enormous flocks are seen 



at sea, and very often covering every available piece of rock. 



ARCTIC SKUA, Stercorarius crepidatus. Often seen in summer. 



RAZORBILL, Alca torda. A regular migrant in both seasons, and 

 also seen fishing in the vicinity in summer. 



GUILLEMOT, Uria troile. Vast flocks seen passing on migration, 



especially in August. 

 BLACK GUILLEMOT, Uria grylle. A few spend the winter in the 



near vicinity of the rock, but never land. 

 PUFFIN, Fratercula arctica. Very rarely seen. 

 LITTLE AUK, Mergus alle. Small flocks are periodically seen in 



winter, generally in January. 

 FULMAR, Fulmarus glacialis. I have never seen this species from 



the rock, but when on board the steamer a few miles from it in 



summer I have never failed to see a few flying about. 



MANX SHEARWATER, Puffinns anglorum. Always numerous in 

 spring and summer. Seen on wing all around the rock, some- 

 times one or two, and occasionally scores. On 6th April 1905, 

 when on board the Hesperus between Dhuheartach Lighthouse 

 and lona, I saw them in hundreds. The sea all the way in 

 about 15 miles was covered with them, and crowds were on 

 wing all around us. I never before or since saw such numbers 

 of them. 



STORM PETREL, Procellaria pelagica. Seen occasionally near the 

 rock towards the end of August and in September at twilight 

 on a dark gloomy afternoon. Have got a few specimens on the 

 lantern. 



THE NORTHERN DIVER is represented by two and sometimes three 

 specimens, arriving in November, and remaining till April, 

 always feeding in close vicinity to the rock. They will at times 

 disappear for a week, and I have more than once seen them on 

 the wing coming out from Tiree, circling round the rock, and 

 settling down a short distance out. On the rock at low water 

 there is a long narrow pool, 20 ft. long, 3 ft. broad, and 4 ft. 

 deep, and the rock all around it, about 3 ft. above water edge, 

 the water escaping at one end amongst loose rocks. On the 



