1882. | FROM PERU AND CHILI. 527 
Larus pominicanus, Licht. 
Larus dominicanus, Licht. Verz. Doubl. p. 82 (1823); Scl. & 
Salv. P. Z. S. 1871, p. 576; Saund. op. cit. 1878, p. 180. 
Five specimens in various stages of plumage from Coquimbo and 
Callao. This widely distributed black-backed Gull appears to re- 
place in the southern hemisphere the northern L. marinus. 
STERCORARIUS POMATORHINUS (Temm.), Saund. P. Z. 8. 1876, 
p- 324. 
3 2, Callao Bay, December 1881. 
Two examples of this circumpolar parasitic Gull, apparently in 
second and third year. These are the first specimens on record 
from the South Pacific, its previous occurrence in that ocean reaching 
no further than the latitude of Inosima, Japan (P. Z.S. 1877, 
p- 800). Callao is also by about three degrees the most southern 
latitude yet reached, Cape York, North Australia, being the nearest. 
It is probably a regular visitant to the Peruvian coast, several ob- 
servers having remarsed medium-sized Skuas pursuing the other 
Gulls, although, until now, the species could not be identified. 
Unless specimens are actually obtained, it is, however, unsafe to 
conclude that any species observed pursuing and robbing other sea- 
birds must necessarily be a Skua of some kind: on the contrary, 
many other Gulls have similar habits, amongst which may be men- 
tioned Larus belcheri and Larus heermanni in the Pacific, Larus 
atricilla (see E. Coues, B. N. W. p. 653), Larus hemprichi in the 
Red Sea, and, in all probability, many more. 
STERCORARIUS CHILENSIS (Bonap.), Saund. P. Z. S. 1876, 
p- 323. 
One, Callao Bay. This locality is the most northern yet recorded 
for this southern representative and close ally of S. catarrhactes of 
the northern hemisphere. 
In a paper recently published by M. Alph. Milne-Edwards (Ann. 
Se. Nat. (6) xii. art. 7), “Sur la Faune des régions australes,”’ he 
inclines to the belief that the type from which the large short-tailed 
Skuas Stercorarius catarrhactes, S. chilensis, and S. antarcticus are 
derived belonged originally to the antarctic regions. The first is 
now confined to the northern hemisphere, in which alone all the other 
known species of Skua have their breeding-places, and the balance of 
probability would therefore seem to be rather in favour of a northern 
origin ; but, after all, this is mere conjecture. With regard to the 
other Gulls I will quote his exact words :—‘‘ Cette étude montre 
que les Goélands et les Mouettes de la région antarctique ne pré- 
sentent rien que puisse caractériser la faune de cette partie du globe, 
et que les espéces ou races qui y vivent sont probablement des dé- 
rivés des oiseaux du méme genre qui abondent dans l’hémisphére 
nord.” It would be unsatisfactory to enter into arguments as to the 
probability of the short-tailed Skuas having had their origin in the 
southern, whilst all the other Gulls had their origin in the northern 
