LAKICE — THE GULLS AND TERNS — STERNA. 



281 



American references. 



Sterna caspia, Lawr. in Baird's B. N. Am. 1858, 859. — Baiud, Cat. N. Am. B. 1858, no. 682. 



COUES, Key, 1872, 319 ; Check List, no. 561 ; 2d ed. 1882, no. 793. — Ridgw. Norn. N. Am. B. 

 1881, no. 680. 



Thalasscus cas^nus, CouES, Pr, Ac. Nat. Sci. Philad. 1862, 537 (part). — Elliot, lllustr. Am. B. 

 pi. 56. 



Sterna (Thalasscus) caspia, CouES, B. N. W. 1874, 667 (part). 



Thalasscus imperator, CouES, Pr. Ac. Nat. Sci. Philad. 1862, 538 (in text ; Labrador). 



Sterna caspia, var. imperator, PiIDGW. Ann, Lye. N. Y. X. 1874, 391. 



Hab. PalKarctic Region. North America in general, but very irregularly distrilnited ; breed- 

 ing in Labrador, along the Arctic coast, on islands in Lake Michigan and along coast of Virginia 

 and Texas ! 1 Humboldt Marshes, Nevada, numerous ; coast of California. 



Sp. Char. Largest of the Terns (wing not less than 15.00 inches). Bill very robust, reddish ; 

 tail short and but slightly forked ; inner webs of primaries wholly dark slaty. Adult, in summer : 

 Entire pileum, including occipital crest and upper half of lores, deep black, the lower eyelid with 

 a white crescentic spot. LTpper parts very pale pearl-gray, fading insensibly to white on the upper 

 tail-coverts, the tail l)luish white ; outer surface of the primaries light hoary ash, their iimer webs 

 uniform slate or dark hoary gray. Rest of the plumage snow-white. Bill deep coral-red, with a 



-"^CsSaJ 



dusky suffusion subterminally, the tip orange or yellowish ; iris dark brown ; legs and feet deep 

 black. Adult, in winter : Similar, Imt the black of the head streaked with white. Young, first 

 "plumage : Similar to the adult, but with the following differences : Pileum (including occiput and 

 upper two thirds of lores) grayish white, thickly streaked with dull black ; side of head with a 

 uniform dull black bar, beginning before and beneath the eye and extending back over upper por- 

 tion of auriculars ; lower portion of lores and auriculars grayish white, mottled with darker gray- 

 ish. Mantle pale pearl-gra}^, sparsely^ marked with irregular spots, mostly inclining to crescentic 

 or V-shaped form, of brownish dusky, the wing-coverts, however, nearly immaculate ; the markings 

 largest on longer scapulars and terminal portion of tertials ; primaries hoary gray, with white 

 shafts, the shorter ones margined with white ; rump and upper tail-coverts immaculate pearly 

 white ; rectrices hoary gray, distinctly spotted with blackish toward tips. Rest of plumage plain 

 white. Bill dull orange (in dried skin), dusky subterminally ; feet brownish (in skin). (No. 93033, 

 9 , Warsaw, 111., Sept. 21, 1883 ; Charles K. Worthen.) Downy young: Above, grayish white, the 

 down of the head dusky grayish at the base ; back and rump finely and indistinctly mottled with 

 VOL. II. — 3t3 



