In addition to its remarkable bodily shape, the adult razorbill is easily recognised by the great lateral compression and subterminal expansion of the beak, from which the bird derives its ordinary vernacular name; as well as by the deep groovings and wide band on the sides of this appendage. The curved white stripe running from just in front of the eye to the root of the beak is another distinctive feature of the species; and this, too, in a more or less distinct form, in birds of all ages, whereas in the young the groovings and white markings on the beak are wanting. Considerable difference exists between the summer and winter plumages of the adult birds. In summer the head and neck are sooty brown, while the back and wings are black with a greenish gloss; the beak and the rest of the under-parts, together with a narrow wing-bar, being white. On the other hand, the winter plumage of the adults, like that of the young in summer, is browner above, while the sides of the head and the fore portion of the neck are of the same snowy white as the under-parts of the body. The razorbill inhabits the coasts on both sides of the North Atlantic, breeding far up on the Norwegian coast, on those of Iceland and the Faröe Islands, and on the opposite side of the ocean on the shores of Newfoundland, Labrador, and Greenland; latitude 70° about marking its northward breeding range on the American side, while in Europe the limit is about one degree less. Eastwards the range extends to Jan Mayen Island; while the southward boundary of the breeding area in Europe appears to be formed by the Brittany coasts. In great Britain these birds breed, in suitable localities, all round the coasts, inclusive of those of the Shetland Islands. These limits do not, however, by any means indicate the whole range of the species, for in winter these birds visit the Mediterranean, and occasionally the Canaries. Throughout the year razorbills associate in large flocks, although in autumn the numbers of these colonies are diminished, apparently by a portion of the birds going out to sea. Bempton Cliffs, on the Yorkshire coast, form one of their favourite breeding-places, where the birds congregate in thousands, in company with guillemots, and yield a large harvest of eggs. The laying season commences about the middle of May, but is at its height some days later; while eggs and young may be found together till late in June. By the end of July the birds have for the most part finished their breeding season, and by the first week in August nearly all have forsaken the cliffs for the sea, which is their true home, and on which they often pass the night. INDEX Abyssinian Green Monkey, 48. _Æx galerita_, 90; _sponsa_, 90. _Alca torda_, 100. _Alces machlis_, 8. _Ammotragus lervia_, 67. _Ara ararauna_, 88; _chloroptera_, 88; _cærulea_, 88; _militaris_, 88; _severa_, 88. _Arctomys bobac_, 72; _marmotta_, 72; _monax_, 72.