246 



AVES. 



and the base of the beak which is covered by the cere (ceroma) is the 

 lore. The form and development of the beak vary extremely 

 according to the special mode of subsistence (fig. 655). 



The tongue, which is always movable, lies on the floor of the 



FIG. 055. Forms of beaks (a, b, c, d, Jc, after Naumaun ; g, i, m, o, regne animal ; I, from. 

 Brehm). a, Phcenicopterus antiquoritm ; b, Plafalea leticorodla ; c, Emleriza citrinellu ; 4, 

 Turdus cyanus ; e, Falco candicans ; f, Mcrgus merganser; g, Pelecanus perspicillatus ; h, 

 Securvirostra avocetta ; i, Rhyncftops nigra ; ^', Columbit liein ; I, alcenicejis rex; m, Ana- 

 sfomos coromandeiianus ; it, Pterogloxsus discolor; o, Ifgeteria senegalensis ; p, FaleineUui 

 ('/ii-'iin ; q, Ci/pselus apits. 



l>uccal cavity. It consists of the horny or fleshy covering of two 

 cartilages attached to the anterior end of the hyoid bone, and serves 

 for deglutition, and frequentlv for seizing food. The buccal cavity, 

 which in the Pelicans is dilated into a large cervical sac supported 

 by the rami of the lower jaw, receives the secretion of a number of 



