Family— CATHAR ACT ID 
Genus— C ATHARACTA. 
Catharaota Bmnnich, Ornith. Boreal, p. 32, 1764 . . . . Type G. shua. 
Also spelt: — 
Cataracta Retzius, ed. Fauna Suecica, p. 160, 1800. 
Cataractes Fleming, Philos. Zool., Vol. II., p. 263, 1822. 
Catarractes PaUas, Zool. Rosso-Asiat., Vol. II., p. 309, 1827. 
Gatarracta Gray, List Gen. Birds, p. 78, 1840. 
Catarrhacta Strickland, Ann. Mag. Nat. Hist., Vol. VII., p. 40, 1841. 
GatarrJiactes Bruch, Joum. fiir Omith., 1853, p. 108. 
Megalestris Bonaparte, Comptes Rendus Sci., Paris, Vol. 
XLIII., p. 643, 1856 . . . . . . . . . . Type G. skua. 
Buphagus Cones, Proc. Acad. Nat. Sci. Philad. 1863, p. 124 Type G. skua. 
On account of anatomical differences, the Skuas have been granted a Family 
distinction from the Gulls and Terns, which are considered only worthy of 
sub-family separation. 
Superficially the bill of a Skua is quite different from that of a Gull on 
account of the presence of a horny cere, extending half way along the upper 
mandible, which overhangs the nostrils. But if a young Skua and a young 
GuU be compared, they will be found to possess very similar bills, and in 
some genera of Gulls (as instance Oabianus) the adult shows a well marked 
transition towards the cere. There seems no reason whatever to doubt the 
very close relationship of Gulls and Skuas, but the inter-relationship of the 
latter is not so clear. 
In my “ Reference List ” I classed the three Skuas which occur in 
Australian waters in the one genus Gatharacta, but this course, I am now con- 
vinced, was most improper. The limits of genera must not be so wide as to 
include such diverse types of birds, while admitting the minute subdivisions 
in the Passeriformes. It would seem that because the birds are big they 
have recently been unfairly treated. It must be acknowledged that the 
evolution of the different tails in the Skuas has most probably taken much 
longer than many of the changes, admittedly generic, in Passerine birds. 
Illogical subdivision, such as that in the A.O.U. Ghecklist, 3rd ed., 1910, where 
two genera are included — the former Megalestris for G. skua Brunnich, the 
second to include 8. poinarinus, 8. parasiticus, and 8. longicaudus — cannot 
be accepted. The latter three show two types as diverse as the first- 
mentioned genus is different from the first member of the second. A 
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