J (EMA SABIN 1. 
487 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed on rocky cliffs, composed of sea-weeds, etc. Eggs, two or three in number, oval in form, yellowish-buff 
in color, spotted and blotched with rounded marks of brown and lilac of varying shades. Dimensions from 1 60 x 220 to 
1-70 x 2-25. 
HABITS. 
The southernmost breeding ground of the Kittiwake Gull, with which I am acquaint¬ 
ed, is Bird Rock, where a few pairs make their homes, placing their nests in the most inac¬ 
cessible portions of the rock. The eggs are deposited about the middle of June, and both 
birds sit.persistently on them until they are hatched. Like other members of the genus,, 
the Kittiwakes are particularly active and noisy during severe storms, and when the huge 
breakers were dashing against Bird Rock, with a fury which sent the salt spray flying over 
the top of the island, producing a continuous thunder, the loud kittiwake , wake , wake , wak- 
er of.the Gulls, came distinctly to the ear, as they flew high over the storm-tossed waves. 
Many Kittiwakes pass the winter in Massachusetts, frequenting the harbors along the coast. 
GENES VI. XEMA. THE FORK-TAILED GULLS. 
Gen - . Ch. Bill, shorter than head and slender. Tail, forked. Hind toe , short. Members of this genus are remark¬ 
able on account of the forked tail. There is but one species within our limits. 
XEMA SABINI. 
Fork-tailed Gull. 
Xema sabini Leach., App. Ross’s Voy.; 1819. 
DESCRIPTION. 
Sp. Ch. Size, small. Form, slender. Color. Adult. Head, back and upper part of wings, slaty-blue. Ring a- 
ronnd neck, edge of wings, spurious quill, and first five primaries, black. Tips of tertiaries, greater part of upper wing 
coverts, and remainder of plumage, white. Bill, black to aDgleand then yellow to tip. Feet, black. Young. Upper parts, 
slaty-gray with the feathers tipped with white. The under parts and tail are white, the latter having a subterminal band 
of black. Wings, similar to adult but with white more restricted. Bill, dusky. 
OBSERVATIONS. 
Known by the small size and forked tail. Distributed in summer throughout the Arctic Regions. Wandering in win¬ 
ter as far south as Massachusetts. Dimensions. Length, 13*75; stretch, 33 - 00; wing, 10*75; tail, 5 00; bill, POO; tarsus, P25. 
DESCRIPTION OF NESTS AND EGGS. 
Eggs, placed on the ground in sandy places, two in number, oval in form, deep greenish-brown in color, obscurely spot¬ 
ted and blotched with darker. Dimensions from P05x P45 to PlOx P50. 
HABITS. 
Although the Fork-tailed Gull has been taken on the coast of Massachusetts several 
times, it is extremely rare and only reaches us in winter, as it breeds in the Arctic Re¬ 
gions, where it is said to nest like the Terns and to have similar habits. 
GENUS VII, PAGOPHILA THE WHITE GULLS. 
Gen. Ch. Bill, shorter than head and very stout. Tail, square. Feet, large and legs stout. Members of this genus 
are very light in color. We have but one species within our limits. 
PAGOPHILA EBURNEA, 
Ivory GuU. 
Pagophila eburnea Kaup., Sk. Ent. Eur. Thier., 1829, 69, 
DESCRIPTION. 
Sp. Cn. Size, medium. Form, robust. Color. Adult. White throughout, with shafts of primaries pale yellowish. 
Young. Similar but mottled with dusky on head, neck, and tips of primaries and tail. 
OBSERVATIONS. 
Recognized by the stout bill and white color. Distributed throughout the Arctic Regions, wandering a little south¬ 
ward in winter. Dimensions. Length, 19 - 50; stretch, 4POO;.wing, 13*50, tail, 6 25;bill, P40; tarsus, P45. 
HABITS. 
•The handsome Ivory Gull is an exceedingly rare visitor, even to the coast of New- 
