XEMA SAB1N1. 487 



DESCRIPTION OF NESTS AND E(!<iS. 



;Y'.<^., placed en rock.v dill's eimipn-ed nl' sen-weeds, etc. yys, two or three in number, oval in form, yellowish-huff 

 in color, spotted and<blotched with rounded murks of brown and lilac of varying shades. Dimensions from 1 OOx'2-JO to 

 1-70 x 2 \>5. 



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. 



GENLS VI. XEMA. THE FORK-TAILED GULLS. 



GEN-. Cn. Dill, 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. Cn. Size, small. Form, slender. COLOR. Adult. Head, back and upper part of wings, slaty-blue. Ringa- 

 ronnd neck, edge of wings, spurious quill, and first five primaries, black. Tipa of tertiaries, greater part of upper wing 

 diverts, and remainder of plumage, white. Bill, black toangleand then yellow to tip. Feet.black. Young. Upper parts, 

 slat.\-^ray w itli the feathers tipped with white. The under parts and tail are white, the latter baring a subtermiiial band 

 of black. Wings, similar to adult but with white more restricted. Bill, dusky. 



OBSERVATIONS. 



Known by th small sizeand forked tail. Distributed in summer throughout tho 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, 1-00; tarsus, I -25. 



DESCRIPTION OF NESTS AND KGGS. 



Eyys, 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 l'05x 1'45 to 1'lOx 1'50. 



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. PAGOPIIILA THE WHITE GULLS. 



(ihv. Cn. Bill, shorter than head and very stout . Tail, square. Feet, larye and leys stout. Members ol this genus 

 are very light in color. We have but one species within our limits. 



PAGOPHILA EBUENEA. 



Ivory Gull. 

 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. 

 Youny. Similar but mottled with dusky on head, neck, and tips of primaries and tail. 



OBSERVATIONS. 



Ki-eoirni/rd I-y tin- -tout liill and while color Distributed throughout the Arctic Regions, wandering a little ^>,ith 

 wan! in winter. DIMIA-IU\>. Length, lll-.'Ki; itMteh, -11-00; wing, i:i'">0, tail, 6 i r >; bill, 1'40, tarsus, 1'45. 



II A KITS. 



The handsome Ivory Gull is an exceedingly rare visitor, even to the coasl of New- 



