210 MR. H. SAUNDERS ON THE LARIN^E. [Feb. 5, 



roughly speaking, as far as 40° N. lat. ; but Messrs. Sclater and Salviti 

 have recently shown me a specimen from Prof. Steere's collection 1 , 

 Mus. University of Michigan, labelled" Macabi, September 1872," 

 and on the card-label "Tumbez," Macabi Island being a little to the 

 north of Huanchacho on the coast of Peru, in nearly 8° S. lat. — an 

 enormous extension of its previously known limits. It is in adult 

 plumage, with the exception of some dusky feathers on the nape ; 

 the forehead and head are white and devoid of the hood, which it 

 was reasonable to suppose would only be worn duriug the breeding- 

 season, although this is the first absolute proof I have had of this ; 

 the bill as in adults ; the tail white and well-forked ; feet rather 

 faded. I imagine this to be a bird of the second year. This species 

 has once occurred at the Bermudas. 



The name of X. collaris was applied to this species as a synonym 

 in the 8vo edition of Ross's 'Voyage' (1819), under the erroneous 

 impression that this was the L. collaris to which Prof. Schreibers, 

 then Director of the Vienna Museum, had given that MS. and un- 

 published name ; but as a matter of fact that name belongs to an 

 example of Rhodostethia rosea. For the elucidation of this point I 

 am indebted to the kindness of Herr A. von Pelzeln, who also iu- 

 forms me that the Vienna Museum is the possessor of what is pro- 

 bably the oldest specimen of this species in any European collection, 

 it having been received, without any published name or description, 

 from the Ornithological Institution of that city about 1806. 



49. Xema furcatum (Neboux). 



Mouette a queue fourchve, Neboux, Rev. Zool. 1840, p. 290. 



Larus furcatus (Neboux), Voy. 'Venus,' Atlas, pi. x. (1846); 

 Prevost & Des Murs, Voy. ' Venus,' v. Ois. p. 277 (1855). 



Xema furcatus, Bruch, J. f. Orn. 1853, p. 103. 



Creayrus furcatus, Bp. Naumannia, 1854, p. 213; Bruch, J. f. 

 Orn. 1855, p. 292 ; Salvin, Tr. Zool. S. ix. p. 506 (Galapagos). 



Hah. The type of this species in the museum of Paris is said to 

 have been obtained at Monterey, California, in November, by Dr. 

 Neboux of the French frigate 'Venus.' The only other specimen 

 known to exist is in the British Museum, and was obtained during the 

 voyage of H.M.S.'s 'Herald' and 'Pandora,' at Dalrymple Rock, 

 Chatham Island, Galapagos group. The 'Herald' appears to have 

 visited Chatham Island between the 11th and 16th January, a date 

 which is worth bearing in mind, as the British-Museum specimen 

 seems to be in fully adult plumage ; the grey tint which pervades the 

 lower part of the neck and breast in the Paris specimen, and which is 

 probably a sign of comparative immaturity, having disappeared, leaving 

 the hood well defined. But for the absence of the distinct collar at 

 the bottom of the hood, and the narrow white baud of feathers at 

 the base of the upper mandible, this bird might be briefly described 

 as a gigantic Sabine's Gull, the tail being rather more forked in 

 proportion than in that species. It is certainly remarkable that, in 

 spite of the researches of the American naturalists, no other spcci- 



1 See above, p. 141. 



