142 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
The whole of the plumage deep leaden-grey ; the upper and under tail coverts 
being lightest ; bill red at the base, black at the tip ; feet black. 
Habitat, Galapagos Archipelago {October). 
This species of gull has many characters in common with the Larus licemato- 
rhynchus of King, from the continent of S. America ; but may at once be distin- 
guished from it by the general extreme duskiness of its plumage, feet, tarsi, and 
bill ; and by the more elongated form of the latter. My specimen was killed at 
James Island. I observed nothing particular in its habits. It is the only species 
of gull frequenting this Archipelago. 
2. Larus klematorhynchus. King. 
Larus heematorhynchus, King , Zool. Journ. iv. 103. 
= Jar cl. fy Sell. 111. Orn. p. 1 06. 
This bird was killed at Port St. Julian on the coast of Patagonia. Beak 
(when fresh killed) of a pale “ arterial blood red,” legs “ vermilion red.” 
3. Larus dominicanus. Licht. 
Larus dominicanus, Licht. Oat. 82. sp. 846. 
Grande Mouette, Azara, No. 409. 
This gull abounds in flocks on the Pampas, sometimes even as much as fifty 
and sixty miles inland. Near Buenos Ayres, and at Bahia Blanca, it attends 
the slaughtering-houses, and feeds, together with the Polybori and Cathartes, on 
the garbage and offal. The noise which it utters is very like that of the common 
English gull {Larus canns, Linn.) 
Xema (Chroicocephauus) cirrocephalum. G. R. Gray. 
Larus cirrocephalus, Vieill. Nov. Diet. d’Histoire, 21. p. 502. 
Larus maculipennis, Licht. Cat. 83. sp. 855. 
Larus glaucodes, Meyen , Nov. Act. 1839, p. 115. pi. 24. 
Mouette cendree, Azara, No. 410. 
This species so closely resembles the Xema ridibundum , Boi&, that Mr. Gould 
observes, he should have hardly ventured to have characterized it as distinct ; 
but as M. Vieillot and Meyen have deemed this necessary, he adopts their view. 
I have compared a suite of specimens, which I procured from the Rio Plata, the 
coast of Patagonia, and the Straits of Magellan, with several specimens of the 
Xema ridibundum ; the only difference which appears to me constant, is that the 
primaries of the X. cirrocephalum, in the adult winter plumage, both of male and 
female, are tipped with a white spot (a character common to some other species), 
whereas in the X. ridibundum the points are black. The beak of the latter species, 
