330 



SYSTEMATIC ZOOLOGY 





which are found in birds are the horny epidermal scales, which 

 are very common on the legs and feet ; bony plates, or scutes, 

 never occur. In some male birds there are also spurs on the 

 legs ; these are likewise horny structures. Both upper and 



Fig. 332. Various forms of beaks, a. Phcenicopterus aniiquorum ; b, Platalt 



c, Ember isa citrinella ; d, Tardus cyan us; e, Falco candicans ; f, Mergus 



Pelecanm I hit us ; h, Kecurvirostra 'a; i, Rhynchops nigra ; k, Colun, 



/, Balaniceps rex ; ;//, Anastomos coromandelianus ; 11, J''. ■ Mycteria 



senegaler, Falcinellus igneus ; q, Cypselus apus. (From Claus and Sedgwick's 



Text-book. ) 



lower jaws are inclosed in a hard, horny sheath constituting the 

 beak (Fig. 332), at the root of which is a mass of naked skin, 

 called the cere, and near this in the upper beak lie the ex- 

 ternal nasal openings ; the organ of smell is poorly developed 

 in birds. The eyes are provided with eyelids, and are capable 



