196 LARIDiE. 



ii. p. 351 (1883) ; Coues, Key N. Amer. B. 2nd ed. p. 750 



(1884). 

 Atricilla catesbyi, Bruch, J.f. O. 1855, p. 287 ; Heine Sf Reichenoio, 



Nomencl. Mus. Hein. p. 359 (1890). 

 Atricilla megalopterus, Bruch, J.f. O. 1855, p. 287. 

 Atricilla micropterus, Bruch, J.f. 0. 1855, p. 288. 

 Atricilla catesbsi, Bjj. C. R. xlii. p. 771 (1856) ; Loche, Expl. Sc. 



Alger., Ois. ii. p. 189 (1867). 

 Atricilla macroptera, Bp. C. R. xlii. p. 771 (1856). 

 Atricilla minor, Bp. C. R. xlii. p. 771 (1856). 

 Chrcecocephalus atricilla, A. Sr K Neivton, Ibis, 1859, p. 371 (S. of 



St. Croix, W.I., and St. Thomas) ; Coues, Pr. Philad. Acad. 1871, 



p. 40 (N. Carolina) ; Allen, Bull. Harv. Coll. ii. p. 366 (1871 : 



Florida). 

 Larus (Chroecocephalus) atricilla, Coues, B. N.- West, p. 650 (1874). 



Adult male in hreeding-plumage. Head and upper neck dark 

 sooty black ; an elongated white patch above, and another below 

 the eye ; lower neck, tail, and the under surface white, with a 

 slight rosy tinge on the latter ; mantle slate or lead-grey (decidedly 

 less blue than in L. frmiklini) ; secondaries broadly tipped with 

 white, as are the four inner primaries ; the next quill (descending) 

 similar, but with a faint edge of black to the inner web ; the two 

 following darker grey above, with broad black subterminal bands, 

 the next two almost black: all of these with white tips ; the outer- 

 most quill wholly black ; under wing-coverts white, passing into 

 grey at the quill-lining : bill lake-red ; tarsi and toes duU red 

 (drying reddish brown). Total length 16-5 inches, culmen 2, 

 wing 13, tail 5-25, tarsus 2-1, middle toe with claw 1-75. The 

 female appears to be a trifle smaller on average. 



Advlt in winter plumage. Like the above, except that the head 

 is white, streaked and mottled with dark grey, while the bill, tarsi, 

 and toes are nearly black. The new primaries have attained their 

 fuU development early in March, by which time the roseate tint on 

 the underparts {said to be lost in winter) has certainly reappeared. 



Immature. Similar, but the head, nape, and sides of the neck are 

 streaked with ash-brown ; the secondaries have dark markings next 

 the shafts ; the five outer primaries sooty black, untipped with 

 white, and the two following with only small white tips ; tail- 

 feathers greyish, with more or less of a black subterminal bar on 

 aU, or on aU except the central pair, according to age. 



Young (autumn). Upper parts mottled with ash-brown ; primaries 

 chiefly dark brown ; tail-coverts white ; rectrices dark grey at the 

 basal portion and umber-brown subterminally, tipped with white ; 

 abdomen white ; breast, under wing-coverts and flanks mottled 

 with ash-brown ; tarsi and toes dark brown. At an earlier age 

 (August) the ash-brown on the upper parts is more pronounced, and 

 the feathers of the mantle are edged with warm buff. 



Nestling. Tawny buff, spotted and mottled with dark brown on 

 the upper surface, throat, and flanks. 



Hah. North America, chiefly on the East Coast and its tidal 

 waters, down to the Mexican Gulf and West Indies (breeding) ; on 



