cell 
APPENDIX. 
difference in the size of the sexes, and of their plumage in the breeding 
season, appears to have been hitherto unnoticed ; 
Ins. Ins. Oz. 
The males average in length 7.6, in extent 16.2, and in weight If. 
The females 8.4, 17 2. 
The breeding plumage of the male corresponds minutely with the descrip- 
tion which Temminck has assigned to both sexes : the female has the fore- 
head, crown, and hind-head a uniform deep sooty black, without intermixture 
of orange or red : the band which passes through the eye is a pure white, 
and is larger and better defined than in the male, including more space above 
and in front of the eye ; the black predominates in the back and scapulars, the 
orange bordering of the feathers being smaller and much lighter than in the 
male ; the under plumage is of a deeper and richer brick-red colour, and is 
unmixed with white feathers for a much longer portion of the season : the 
female bird attains her perfect plumage earlier in the year, and retains it 
longer than the male, which is also the case with several other of the northern 
birds. 
15. Sterna Arctica. Arctic Tern. 
Temm. 742 . — Sterna Hirundo. Greenl. Birds, no. 17 
In the Memoir on the Birds of Greenland, it was remarked that a difference 
existed between the Terns of that country, and those of the European coasts, 
in the bill and legs ; the bills of the former being one-third shorter, and their 
tarsi only half the length of those of Europe. Although this difference was 
considered sufficient to have justified a specific distinction, the name of Sterna 
Hirundo was still retained in the memoir, from the conviction that the errors 
which arise from a hesitation to create new species, are less injurious to 
natural history, than those which result from the opposite practice. Mr. 
Temminck, however, , whose very extensive experience gives confidence to 
his decisions, has treated them as distinct species, in his second edition ; and 
in reliance on his authority, the name of Sterna Arctica has been adopted 
