552. Capt. SaniNE's Memoir on the Birds of Greenland, ác. 
called by the different names cited above, during the first year of its 
existence, when its tail is destitute of the long feathers, and its whole 
plumage is marked with transverse bars of light-brown and dingy 
white. The markings do not entirely leave it in the second year, 
but are perceptible in the under parts of the wings and in the 
adjoining under parts of the body: at this period the two centre 
tail feathers have become elongated, the breast and throat have 
become white, though sometimes spotted a little, and the ends of 
the feathers of the back and wing coverts are tinged with brown, 
the crown of the head being dark brown. As the birds advance 
in age the under parts and back of the neck become white stained 
more or less with brown, and the sides and back of the neck are 
tinged with yellow; the crown of the head and the whole u pper 
parts except the neck are an uniform dark brown, and the two 
tail feathers are much lengthened. In all these changes there are 
however considerable variations; and even in the descri ption of 
the immature bird as a separate species, authors have varied ac- 
cording to the age of the specimen before them. F abriciüs's ob- 
servations ascertained that there was no difference between the 
sexes; and as he saw them at their breeding places he must have 
been aware of their difference of plumage in their young state. 
I learn from Mr. Temminck, who has had recent opportunities of 
investigating the history of this bird, that he is satisfied the males 
and females of the same age are alike, and that he is convinced of 
the specific identity of the Larus crepidatus. But the great diffi- 
culty is where to place the birds which have their whole under parts. 
brown: these have been erroneously considered by many as the 
females, and Briinnich made them a distinct species ;—the elu- 
cidation of this point must wait for further investigation. Several 
birds in that state of plumage, but no young ones, were killed 
during the voyage in the Straits. 
25. Pro- 
