This gull, like most of the Laridæ, is a vociferous bird, and his notes--short and rapid, like excited exclamations, or drawn out, guttural in tone, and inflected in various ways--often sound like laughter; hence the name of laughing gull, sometimes given to this species, and the specific name of _ridibundus_. To my ear it is like the guttural and extravagant laughter of the negro, rather than that of the white man. * * * * * Besides the six species described, there are six others, belonging to the sub-family Larinæ (true gulls), which figure in the books as British species. One of these (the second on the list) is perhaps a regular visitor. Ivory gull (_Pagophila eburnea_).--A circumpolar species; occasionally straggles to the British coasts. Glaucous gull (_Larus glaucus_).--Circumpolar in its range; a winter visitor to the northern parts of the United Kingdom. Iceland gull (_L. leucopterus_).--A rare winter visitor (to the north) from the arctic regions. Great black-headed gull (_L. ichthyaëtus_).--A single specimen of this southern species was obtained many years ago in this country. Little gull (_L. minutus_).--An irregular visitor from continental Europe. Sabine’s gull (_Xema sabinii_).--A rare straggler from North America. Common or Great Skua. Stercorarius catarrhactes. [Illustration: FIG. 111.--GREAT SKUA. ¹⁄₁₂ natural size.] Upper parts mottled brown; shafts of the quills and tail-feathers white; under parts rufous-brown; bill, legs, and feet black. Length, twenty-five inches. * * * * *