MOULT OF BILL IN THE PUFFIN. 235 
brown; they have not the red eyelids, nor the horny plates above 
and below the eye, nor have they the puckered yellow skin at the 
base of the bill, and what is still more remarkable, the bill is 
differently formed ; it is neither of the same size, shape, nor colour, 
and the pieces of which it is composed are not even the same. It 
is small, sliced off (tronqué) in front, especially at the lower man- 
-dible, wanting the pleat (owrlet) at the base, and flattened laterally 
on a level with the nostrils, where a solid horny skin of a bright 
lead-colour is replaced by a soft greyish membrane. 
“ Hitherto authors have considered the Puffins found in this state 
to be the young, of different ages, of Mormon arctica.* This view 
was even generally adopted, when M. J. Vian, examining a large 
number of specimens procured in winter on the coasts’ of France, 
and recognizing amongst them both old and young, thought that 
they should be specifically separated from Mormon arctica under 
the name Mormon grabe.t 
“Neither of these views can be admitted. The first falls to the 
ground before the facts which [ am about to detail; as to the 
second, in order to end all doubt, my friend M. Vian, admitting 
that, in view of my recent observations, Mormon grabe -has no 
longer any claim to specific distinction, has made a point of 
assisting me by obligingly placing at my disposal the specimens 
which served him as types. Dr. Marmottan, too, whose ornitho- 
logical collection is rich in material for a study of the fauna of 
France, has entrusted me with his fine series of Puffins. A large 
number of specimens, from all quarters, have in fact been offered 
to me. I shall use them later, when, after another season’s 
observations on the coast of Brittany, | shall make known some 
other interesting points in the history of the Puffin. For the 
present I shall confine myself to a study of the metamorphoses to 
which the beak and the palpebral appendages of these birds are 
subject after the breeding season. 
“It will perhaps be interesting to state here the different stages 
of enquiry through which I arrived at the discovery of the meta- 
morphosis in question. I had for some years remarked that the 
beak of specimens killed on the French coast belonged to two very 
* See ‘The Zoologist’ for 1862, pp. 8003-4 and 1863, p. 8331. 
+ Bull. de la Soc. Zool. de France, 1876, p. 4. M. de Norguet (Bull. Scient. du 
Dep. du Nord, 1877, p. 39) sees in Mormon grabe merely individual varieties of 
Mormon arctica. 
