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Show 294 MR. H. SAUNDERS ON THE GREY-CAPPED GULLS. [May 5, jamesoni, and perhaps L. pomare, into whose specific distinctness it is not m y present intention to enter. Another point which distinguishes it from L. phaocephalus exists in the seventh primary, which has a broad dusky bar right across it and is altogether darker in the grey-capped bird, whilst in L. hartlaubi it is uniform grey, just fringed with smoke-colour on the inner web; the colour of the legs and bill is also deep lake-red. Blasius says (loc. cit.) that, as a rule, L. phaocephalus, Sw., figures as L. hartlaubi in collections; but according to m y experience the reverse is the case ; and, with one solitary exception in the British Museum, all the specimens which I have examined marked "L. phaocephalus" are really L. hartlaubi. Layard (B. S. A. p. 368) has also confounded these two species, having obtained both. When we turn to L. cirrhocephalus of South America we find a different element of confusion, owing to the presence there of a species which certainly has a hood, although in this case it is a brown one, similar to that of our European L. ridibundus. Prince Max. v. Wied first noticed its occurrence amongst the grey-capped species (Beit. iv. p. 854), and was inclined to refer it to L. ridibundus; but it is undoubtedly L. glaucodes, Meyen, Obs. Zool. p. 115-L. albipennis, Licht., Gavia roseiventris, Gould (I only give the principal synonyms)-a species which ranges from the south of Brazil down to the Falkland Islands, throughout Patagonia, and for some distance up the coast of Chili. This is the species of whose breeding near Buenos Ayres Mr. W . H. Hudson (P. Z. S. 1871, p. 4) has given an interesting account; but although he distinctly calls it (P. Z. S. 1870, p. 802, and 1871, p. 258) the black-headed gull, the very name we apply to our L. ridibundus, yet he identifies it with L. cirrhocephalus, whose head, as I have repeatedly remarked, is of a pale grey, and nothing approaching either to black or brown. Excepting that to a casual observer all Gulls of nearly the same size are much alike, it is difficult to understand how the two species can have been confounded even in immature plumage; for the smoke-colour of the under wing-coverts so noticeable in L. cirrhocephalus is entirely absent in L. glaucodes, to say nothing of the markings of the primaries, which differ even in very young birds. That L. glaucodes itself should have been subdivided is not at all surprising; for it requires a large series to show how the primaries, which in the early stages have merely a patch of white near the apex, gradually become barred with black and white (in which stage the brown head of maturity is assumed) and gradually lose all but a streak of black on the outside of the inner web, so that the principal primaries appear to be entirely white. L. maculipennis of Burmeister, however, is L. cirrhocephalus. The sum of my observations is briefly this-that L. phaocephalus, Sw., and L. cirrhocephalus, V., are fairly separable, that L. phaocephalus is totally distinct from L. hartlaubi, Bruch, which never has a hood of any colour whatever, and that L. cirrhocephalus has been unnecessarily confounded with L. glaucodes. M y warmest |