NATURAL HISTORY SOCIETY OF GLASGOW. 211 



aloof from the other species when the latter are fishing, and fly- 

 often in pairs far inland over the mud-flats. Upon other occa- 

 sions, on firing a shot in early morning, when the crowd of gulls 

 was resting on the edge of the mud, I have observed that they 

 almost invariably wing their way to the above-mentioned field; 

 and, when the tide rises, and the fishermen begin drawing their 

 nets, do not, like the other species, flock down to feed on the fish 

 which escape through the meshes, and which struggle for a time 

 near the surface. 



Upon the 15th of January I again paid an early visit to the 

 coast, and took up a position on the pier. Thousands of great 

 gulls — Lams marinus, L. fuscus, L. glaiicns, and L. argentatus — 

 were massed together on the mud-edge, and on examining them 

 carefully with my glass, I could distinguish many of the more 

 slender-built Iceland Gulls amongst them. At length one adult 

 Iceland Gull flew past me, and I fired, but ineff'ectually. With 

 the rushing noise of many wings, the great body of gulls rose, 

 at the report of the gun, and, along with other flocks lower down 

 the firth, winged their way, as before, inland, and the air became 

 filled as by a snow-drift. 



Before they all took wing, however, I had a good opportunity 

 of comparing the Glaucous and Iceland Gulls when at rest, and 

 the experiences of this, and of another trip combined, have led me 

 to the following conclusions : — Apart from the inferior size of 

 L. leucopterus, which in itself alone cannot be accepted as a 

 criterion for distinction, this species can be separated by the field 

 naturalist from the Glaucous Gull, by its neater, more slender 

 appearance, standing higher on its legs, having a more cuneate 

 shape posteriorly, and the wings more tapering when closed. 

 Further, it appeared to me that the Glaucous Gulls when resting 

 on the mud, and with the wings closed, carried the tips of the 

 wings higher than the end of the tail, but that the Iceland Gulls 

 carried their wings on the same, or nearly the same level as the tail ; 

 thus imparting to these birds a more tidy, trim appearance than 

 their big brothers possessed. Those who have watched the tame 

 goose of our farm-yards, and have had opportunities of comparing 

 with it the lighter, handsomer form of the tamed Grey-lag Goose 

 {Ajiser fenis), will more easily understand some of the comparisons 

 I have above drawn. 



When flying, the action of the Iceland Gull is more airy and 



