LARID.E — THE GULLS AND TERNS — XEMA. 



273 



met with this species at St. iVIichael's, where a few individuals made their appearance 

 about the salt-marshes on the 7th of May, and a few pairs bred there. They were 

 often feeding about the mud of the lakes, but lie did not see any of them on the sea- 

 shore. Their food consisted of worms and insects. They were very bold, dashing 

 like the Kittiwakes at the head of any intruder upon their domain ; at other times 

 they were rather shy and wary. 



Eggs of this species, procured on the Arctic coast by Mr. MacFarlane, exhibit the 

 following measurements: 1.75 by 1.20 inches; 1.70 by 1.25; and 1.76 by 1.20. They 

 are of nearly uniform appearance, size, and shape. Their ground-color is a deep 

 olive-brown, varying to greenish in some, to a deeper olive in others, and spotted 

 witli markings of a deep sepia, with no obscure cloudings of slate or lilac. 



Xema furcata. 



THE SWALLOW-TAILED GULL. 



Mouette ii queue fourcliuc , Neboux, Rev. Zool. 1840, 290. 



Larus furcatus, Neboux, Voy. "Venus," Atlas, pi. x. (1846). — PuEVOST & Des Murs, Voy. 



"Venus," V. Ois. 1855, 277. 

 Larus (Xcma) furcatus, BiiucH, J. f. 0. 1853, 103. 

 Xema furccdum, CouEH, Key, 1872, 317; Check List, 1873, no. 559; Birds N. W. 1874, 661.— 



Saunders, P. Z. S. 1878, 210 ; 1882, 523, pi. 34 (adult and young ; Peru). 

 Xcma furcata, Coues, 2d Cheek List, 1882, no. 791. 

 Crcagrus furcatus, Box.vp. Xaumannia, 1854, 213. — Lawk, in Baird's B. N. Am. 1858, 857. — 



Baird, Cat. N. Am. B. 1859, no. 679. ^Salvix, Trans. Zool. Soe. IX. 1876, 506 (Galapagos). 



— RiDGW. Xom. N. Am. B. 1881, no. 678. 



Hab. Coast of California ? ; Galapagos ; Paracas Bay, Peru (Saunders). 



Sp. Char. Adult (summer fhhmage ?) : Above, cinereous ; entire head, with anterior half of 

 the neck, sooty black ; frontal bar, exterior margin of the scapulars, under wiiig-coverts, tail, and 

 entire lower parts, white ; first to f"ourth quills, with tlie whole of the outer and the terminal 

 portion of the inner webs, black, the third and fourth gray at the base ; fifth and sixth gray 



X. furcata, summer adult. 



exteriorly, black terminally ; fourth, fifth, ami sixtli with a white apical l)ar. Bill and feet red. 

 Total length, 23.00 inches; wing, 16.00; middle rcctrices, 4.70; exterior rectrices, 8.00 ; tarsus, 

 1.90 ; middle toe, with claw, 2.00.1 



1 Translation of Salvin's Latin diagnosis in Trans. Zool. Soe. Lend. IX. 1876, p. 506. 

 VOL. II. — 35 



