290 
Mr. Montagu's Observatiom 
assumes more of the dusky or brown feathers than usual ; while 
the middle coverts of the wings retain the mottled brown, and the 
tail the dusky bar at the end. This, though we consider it as an 
irregular change, may be admitted as an unusual variation in the 
gradations commonly observed ; for scarce an instance is to be 
found but what the brown scapulars and middle series of the 
wing coverts are changed for those of gray, and the tail becomes 
wholly white before the head is so much as covered with dusky 
feathers, or the legs become more than reddish. 
The fourth change is that which has been generally known by 
the Red-legged Gull. Lath. Syn. vi. p. 381. Larus cinerarius 
Gmel. Sijst. ii. p. 597- Larus ridibundus Lnd. Orn. ii. p. 812. var. /3. 
and in the Orn. Diction, is given under the title of Gull-red-legged 
with a reference to Gull-black-headed. 
In this change, which brings it so near maturity, we find a very 
material difference ; for not only the scapulars and coverts of the 
wings are become gray, but the bar at the end of the tail is lost, and 
that part assumes a pure white ; the legs and bill also become of 
a fine purplish red ; these last, however, grow darker as the spring 
advances, and the black increases on the head, a circumstance we 
believe peculiar to the breeding season, when that colour spreads 
over the whole of the head, taking in the throat; and in this, the 
most perfect or adult state, it is the Black-headed Gull. Lath* 
Si/n. vi. p. 380. Larus ridibundus Gmel. Syst. ii. p. 601. hid. 
Orn. ii. p. 811. 2. and the Gull-black-headed of the Ornithological 
Dictionary. 
Having now traced the Black-headed Gull through its various 
stages of plumage, after long experience and investigation, we 
trust the numerous synonyms will, in future works on Ornitho- 
logy, be concentred to one species, Larus ridibundus. 
THORACIC 
