LARID.E — THE GULLS AND TERNS — XEMA. 



273 



met with this species at St. Michael'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 he 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 

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



Xema furcata. 



THE SWALLOW TAILED GULL. 



Mouelle a queue fmirchur, Neboux, Rev. Zool. 1840, 290. 



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



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

 Larus (Xema) furcatus, Bruch, J. f. O. 1853, 103. 

 Xema furcat.um, l'oues, Key, 1872, 317; Check List, 1873, no. 559; Birds N. W. 1874, 661.— 



SAUNDERS, P. Z. S. 1878, 210 ; 18S2, 523, pi. 34 (adult and young ; Peru). 

 Xema furcata, Coues, 2d Check List, 1882, no. 791. 

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



Baird, Cat. N. Am. B. 1S59, no. 679. — Salvix, Trans. Zool. Soc. IX. 1876, 506 (Galapagos). 



— Ridow. Noni. N. Am. B. 1881, no. 678. 



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



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

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

 entire lower parts, white ; first to fourth quills, with the whole ot the outer and the terminal 

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



X. furcata, 



• adult. 



exteriorly, black terminally ; fourth, fifth, and sixth with a white apical bar. Bill and feet red. 

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

 1.90 ; middle toe, with claw, 2.00. 1 



1 Translation of Salvia's Latin diagnosis in Trans. Zool. Soc. Lond. IX. 1876, p. 506. 

 vol. ii. — 35 



