Capt. SàgixE's Memoir on the Birds of Greenland, dc. 551 
23. Larus Sagini. — Forked-tailed Gull. 
A fall description of this bird having been already presented to - 
the Society*, it is unnecessary to repeat the account. 
Mr. Temminck informs me that he has seen this bird in the 
Museum at Vienna, where it was proposed to call it Larus colla- 
ris, but that it has not been described by the ornithologists of that 
capital, or by any author whatsoever before the Memoir above 
referred to was presented to the Society. The specimen, he thinks, 
was obtained from Professor Giesecké ; but the bird is not to be 
found in a MS. list of Greenland birds in his own hand-writing, 
with the sight of which I have been favoured by Mr. Bullock, nor 
is any other Gull there mentioned with which it could possibly 
have been confounded. 
24. LrsrRis PARASITICUS. 
Catharacta Parasitica. Fabr. 105. 
MATURE. Larus Parasiticus. Gmel. ii. 601. Lath. Ind. Orn. à. 819. Faun. 
Suec.55. Miill.no.166. Temm.519.—Arctic Gull. Br. Zool.ii. 179. Arct. Zool. ii. 
530. Lath. Syn. vi. 389. Mont. Dict.& Supp.— Catharacta Parasitica. Brün. no. 197. 
IN BROWN PLUMAGE. Catharacta Coprotheres. Briin. no. 128. : 
IMMATURE. Lestris Crepidatus. Temm. 515.—Larus Crepidatus. Gmel. ii. 602. 
Lath. Ind. Orn. ii. 819.—Black-toed Gull. Br. Zool. ii. 178. Arct. Zool. ii. 531. 
Lath. Syn. vi. 387. Supp. 268. Mont. Dict. & Supp.—Larus Cepphus. Müll. no. 168. 
— Catharacta Cepplius. Brün. no. 126. 
I have followed the example of Temminck in removing this 
with the other dark-coloured Gulls from Larus and giving them 
the generic appellation of Lestris. Much inaccuracy as well as 
difference of opinion has existed respecting not only the imma- 
ture, but the mature birds of this species. ‘The immature bird 
has been described as a distinct species. Montagu was the first 
author who had a doubt of the correctness of this arrangement, but 
he erred in considering the young bird as a variety only. It has been 
* See page 520 of this volume. e fled 
