This Gull, which is similar to the Great Black-backed, but is smaller and has a lighter mantle, does not breed in any considerable numbers on the American side of the Pacific. It nests in June on some of the islands in Bering Sea and probably more commonly farther north. They often nest in company with other species, placing their small mounds of seaweed on the ground on the higher parts of the islands. The full set contains three eggs of grayish or brownish color, spotted with dark brown or black. Size 2.90 × 2.00. Data.--Harrowby Bay, N. W. T. Canada, June 11, 1901. Nest of grass, roots and mud and lined with dry grass; on point making into the bay. Collector, Capt. H. H. Bodfish. [Illustration 045: Great Black-Backed Gull. Kumlien's Gull.] [Illustration: Grayish buff.] [Illustration: right hand margin.] Page 44 49. WESTERN GULL. _Larus occidentalis._ Range.--Pacific Coast, breeding from southern California to British Columbia. This bird, which is the most southerly distributed of the larger Gulls is twenty-four inches in length. Mantle slate colored; primaries black, both these and the secondaries being broadly tipped with white. These Gulls nest abundantly on the Farallones, the majority of them showing a preference for the lower portions of the island, although they nest on the ledges also. Besides man, these Gulls are the greatest enemies that the Murres have to content against. They are always on the watch and if a Murre leaves its nest, one of the Gulls is nearly always ready to pounce upon the egg and carry it away bodily in his bill. The Gulls too suffer when the eggers come, for their eggs are gathered up with the Murres for the markets. They make their nests of weeds and grass, and during May and June lay three eggs showing the usual variations of color common to the Gulls eggs. Size 2.75 × 1.90. 50. SIBERIAN GULL. _Larus affinis._ This bird does not nest in North America, and has a place on our list, by its accidental occurrence in Greenland. It is an Old World species and its nesting habits and eggs are like those of the Herring Gull. 51. HERRING GULL. _Larus argentatus._ Range.--Whole of the Northern Hemisphere, breeding from Maine and British Columbia northward and wintering south to the Gulf.