24 LARUS LEVCOPTERUS. 



Piiiiifli'ifS and reiaaindci' of pluinajfc, white. Bill, yellow, iri-;, white, and feet, pinki^li. J/i winlcr, similar hut .'Strcaiced 

 on head and neck with asliy-bruwn. Young. Similar to winter adult but streaked and .-potted with a-hy-bruvvn. 



OISSKRVATIONS. 



IJccognized by the lar.sc ."^ize and white primaries. Distri'mted, in summer, tliroui;hout the Arctic Regions, wander- 

 ing a.sfar. south asMassacluisctts in winter. DiMEXSioNS. Length, 30'00; stretch, 6'2-00; wing, I8i50, tail, 8'75; bill, 3'00; 

 tarsus, 3-00. 



DESCRIPTION OF NESTS AND ECiCJS. 

 I^tsl!,, placed on rocky cliffs, composed of sticks, sea-weeds, etc. Eggs, three or four in numlier, oval in form, vary- 

 ing from ))luish-\vhite to dark hrownish-yellow in color, spotted, blotched, and sprinkled with brown and lilac of varyin" 

 shades. Dimensions from ■2'18xi!'95 to y'25x3 00. 



II A CITS. 



The large tiiul liamlsoinc Gl;iucou.s Gull i.s extremely nire on our New England coast 



in winter, but i.s oectisionally taken a.s far south a.s Massachu.setl.s, both in the adult and 



immature plumages. I letirned, however, when on the Magdalen Islands, thiit it is quite 



common there in winter. This bird has much the same htibits as these of the larger Gulls. 



LARUS LEUCOPTERUS. 

 Wiiite-wingecl Gull. 

 Larus leucopicrus ¥.\n., Prodr. Isl. Orn., 1820, 91. 

 DESCRH'TION. 

 Sr. Cii. Size, medium. Form,roliust. CoLon. Adult. Back and upper part of wings, pale pearly-blue, witli prima- 

 ries and remainder of plumage, white. Iris, white, bill, greenish-yeHow, and feet, pinkish. Winter adult. Similar but 

 with head and neck narrowdy streal;ed with dusky. Young. Pale yell'owisli-l)rown thruugliout, faintly mottled with 

 darker, and witli primaries dusky at tips. Bill, dusky. 



(JIJSERVATIONS. 

 Known liy the medium size and pale color. Distributed, in summer, throughout the Arctic Regions. Winters from 

 M.assachusetts, northward. Dime.vsions. Length, -illS; stretch, 52-00; wing, 16-75; tail; 6-55; bill, l-9t>; tarsus 2-55. 



DESCRIl'TION OF NESTS AND EGGS. 

 Nests, placed on rocky cliffs, composed of sticks, , sea-weeds, etc. Eggs, from three to four in number, oval in form, 

 dee|i brownish-yellow in color, spitted and bhitched with ratlier round mark.s of brow-n and lilac of varying shades. Di- 

 mensions from 1 85 .-i 270 to -i-liO x 2-7f>. 



HABITS. 



On the thirty-first day of January, 1880, an immature White-winged Gull was brought 

 to me by the Btings Brothers for identifictition. It was killed while flying over the Mill- 

 diim, in Boston, near Chtirles River, and iinothcr was seen at the .same time. This is the 

 only specimen of this rtire bird that I ever saw in the Oesh, and consider it of very uncom- 

 mon occurrence as f;ir south as Massachusetts, as it breeds in the Arctic Regions. 



LARUS MARINUS. 



Great Black-backed GuU. 



Larus marmus Linn., Syst. Nat., I; 1766, 225. 



DESCRIPTION. 



Sp. Ch. Size, very large. Form, robust. Colok. Adult. Back and wings, dark-slaty, becoming black on prima- 

 ries, which with secondaries and tertiaries are broadly tijjped with white. Remainderof plumage, wiiite. Iris yellowish- 

 white, bill, yellow, with a venuilion spot near tip of under mandible, and feet, pinkish. Winter adult. Similar but with 

 head and neck streaked with dusky. Young. Ashy-brown throughout, more or les.s mottled with white. Pruuaries and 

 tail, dusky. Bill, black. 



OBSERVATIONS. 

 Known by the large size and dark colors above, in adult, and rather palecolors in young. Distributed in summer from 

 Bay of Fundy, northward. Winters from Maine to Florida 



DIMENSIONS. 

 Average measurements of specimens from North America. Length, 30-50; stretch, 65-00; wing, 19-20; tail 8-48- bill 

 2-38: tar.sus, 2-87. Longest specimen. 31-00; greatest extent of wing, 66-00; longest wing,20-25; taiCo 05- bill 2-'5''- tarsus' 

 3-05. Shortest specimen, 30-00, smallest extent of wing, (il'dO; shortest wing, 1786; tail, 7-98; bill, 2-25- tarsus 0.75 ' ' 



