418 LARID. 
This is a South-American species, found throughout the greater part of that continent, 
and ascending the large rivers for thousands of miles, even to the Huallaga and the 
foot of the Eastern Andes. Mr. Saunders also states that it occurs on Lake Titicaca, 
and is found along the Pacific coast, from the Straits of Magellan to Peru, and up the 
Guayaquil River as far as Babahoyo. 
A single specimen from Cozumel Island has been identified by Mr. Howard Saunders 
as belonging to the present species. This locality is far beyond any range of /. melanura 
previously recorded. The following observations are copied from his volume of the 
‘Catalogue of Birds’ 2:—“ The specimen from Cozumel has distinctly smoke-coloured 
under wing-coverts, and shows no trace of white on the parapteral feathers; the 
rectrices are chiefly dark, but the white on their edges is rather wider than in 
typical R. melanura, and so is the whitish band on the wing. ‘The fact that the 
North American R. nigra visits Cozumel is not without significance.” 
Subfam. LARINAL. 
In this subfamily are to be found all the Gulls, large and small, the characteristic 
feature of the group being the form of the upper mandible, which is the longer, and is 
bent down over the tip of the lower mandible, thus distinguishing the Gulls from 
the Terns, in which the bill is slender and both mandibles are of equal length. ‘The 
tail is usually square, in a few instances forked, and on still rarer occasions wedge- 
shaped. 
The Larine are practically cosmopolitan, being found at some period of the year in 
every quarter of the globe. 
LARUS. 
Larus, Linn. Syst. Nat. i. p. 224 (1766) ; Saunders, Cat. Birds Brit. Mus. xxv. p. 169 (1896). 
In the Gulls of the typical genus Larus the tail is not forked, but is square or very 
nearly so; the hind toe is moderately or well developed and free, and the lower third 
of the tibia is bare. The bill is always more than twice as long as it is deep, and is 
sometimes thrice as long, the nostrils being linear or linear-ovate. 
Forty-four species of Gulls are recognized by Mr. Howard Saunders, of which seven 
occur in Central America. Two only, however, are known to breed there, the rest being 
winter visitants from more northern regions. 
1. Larus philadelphia. 
Sterna philadelphia, Ord, in Guthrie’s Geogr. 2nd Amer. ed. ii. p. 819°. 
Chroicocephalus philadelphia, Dugés, La Nat. i. p. 142°; Lawr. Mem. Bost. Soc. N. H. ii. p. 317°; 
Sanchez, La Nat. i. p. 108°. 
Larus philadelphia, Baird, Brewer, & Ridgway, Water-Birds N. Amer. ii. p. 260°; A. O.U. Check-l. 
