APPENDIX. 
463 
grey winter feathers of head and neck falling off, and new white ones 
appearing. In a bird shot so early as the 12th of this month, in 
1846, the neck was pure white. 
March 10, 1849. Adult shot to-day, exhibited pure white plumage 
on head and neck, and other new white feathers were in pens. 
Laras ridibundus. March 16, 1848. — Two of these birds, shot to- 
day, were brought to me to prove that the white feathers of the 
head fall off in spring, and are replaced by wholly new black feathers. 
One bird was perfectly adult, and did show this ; the black feathers 
being so far advanced beneath the white ones, that when these latter 
drop off, the head is perfectly clothed in black, which accounts for the 
sudden transition that takes place. There are many pen feathers through- 
out the entire neck of this bird, as in that of the herring-gulls exa- 
mined a few days ago — a circumstance which I note in consequence of 
the change of colour being confined to the head in the one species, 
and prevailing throughout the neck in the other. 
April 16, 1850. An adult bird of this species obtained by Dr. 
J. D. Marshall, last October, retained (as he informs me) its winter 
plumage on the head (pure white, with the black ear-spot) until the 
6tli of April, when it commenced getting black, and on this day had a 
perfect black head, having been just ten days in acquiring the change. 
July 14, 1850. I examined Dr. J. D. Marshall’s living bird, already 
noticed, and a finer mashed gull ( L . capistratus ) , as to form of mask 
and its pale broccoli-brown colour , could fiot possibly be. 
Larus cams. March 7, 1849. — An immature bird, having a few 
feathers only of adult plumage on the back, has the entire feathers of 
the throat new. 
Larus rissa. February 1849 (end of). — Grey winter feathers of 
head and neck dropping off in an adult bird, and new white feathers 
appearing. 
Alca torda. February 25, 1848. — An adult razorbill, killed at 
Strangford Lough on the 22nd, was brought to me in the flesh, that I 
might see the state of plumage of its neck and head. "Forehead and 
top of head (which are black in summer and winter) exhibit both 
old and new black feathers. Feathers on sides and back of neck either 
white or black, the white falling out, and young black rising to supply 
their place : the black are sufficiently grown to completely clothe the 
bird before the white ones fall out. There is no moult going on in 
