522 RISSA TRIDACTYLA. 



Bill (lark brown, with patches of greenish-yellow ; angle of 

 the moutli bright orange ; edges of eyelids dark brown, 

 tinged with orange ; iris deep brown. Tlic plnniage purt.- 

 white ; but the back of the head mottled with pale blue ; 

 the hind-neck of that colour; a deeper spot of the same 

 behind the ears, and the preocular bristly feathers blackish ; 

 the lower hind-neck nearly white ; the back and wings pale 

 blue ; the middle wing-coverts dark brow n, forming an irre- 

 gular bar, Avhich is longitudinal, when the wing is closed ; 

 the alula, outer webs of the first five primary coverts, outer 

 web, half of the inner longitudinally, and tips of first four 

 primaries, together with the tips of the next two, blackish- 

 brown. 



In summer the plumage is that of the adult at that 

 season, and in the next autumn is as follows : — 



Adult in Winter. — The plumage as described in sum- 

 mer, only the hind-neck, its sides, and part of the head are 

 light bluish-grey. 



Remarks. — The specific name tridactyla is not strictly 

 correct, inasmuch as the bird has four toes, although one is 

 so small as hardly to deserve being considered as such. Nor 

 is the generic name Rissa better, it being barbarous and 

 meaningless. But I feel that I must leave the final refor- 

 mation of ornithological nomenclature to a Linna;us, wiser 

 and more consistent than the first. All that I can do is to 

 try to rectify the most glaring errors. As every species 

 must have an English specific name, I have chosen Black- 

 footed in preference to Grey-backed or Three-toed, because 

 the single character indicated by it, together with tliat 

 pointed out by the Latin specific name, will suffice at once 

 to distinguish this from any other British bird of the family 

 that may occur to the student. 



