prey never drink ; on the contrary, however, we have 

 remarked both Ossifragus and this species, to be fond 

 of water, and not merely to sip like other birds, but 

 to take a continued draught. Our living specimens 

 not unfrequently bathe, by plunging over head in a 

 large tub of water, provided for that purpose. 



In August, 1816, two young birds of this species, were 

 to be seen at the inn, at Dalwhinne, Highlands, Scotland, 

 near to which place they were taken from the nest. W. 



4. ALBICILLA. CINEREOUS EAGLE, GREAT 



ERNE, OR WHITE TAILED EAGLE. 



F. Fusco-cinereus, capite colloque canis, cauda alba. 

 Shaw. 



The bill, cere, irides,* and legs, are pale-yellow, 



* The nictitating membrane, which birds possess for the 

 purpose of moistening the eye, defending it from injuries, 

 and particularly for excluding excessive light, is situated at 

 the upper part of the inner canthus of the eye ; it is semi- 

 transparent and elastic, and is drawn over the whole ante- 

 rior part of that organ by two muscles, the quadratus and 

 pyramid alis ; on the birds ceasing to exert those agents, it 

 recedes by its own elasticity. 



Would it not be better for authors to confine the name 

 Membrana nictitans to the semi-transparent and elastic 

 membrane possessed by birds, and term the process of the 

 conjunctiva, found in many Mammalia, Palpebra tertia only : 

 and to the still smaller doubling in the human eye, keep to 

 the general anatomical name Valvula semilunaris ? 



The external eyelids in birds, are chiefly closed by the 

 elevation of the lower one, 



