THE riGEON. 



189 



s.aii an 



FIG. 47. Columba livia. The skull of a young bird (about six 

 weeks old). A, from above ; B, from beneath ; C, from the left side 

 (naf. size). 



The cartilaginous parts are distinguished by dotting. 



al.s, alisphenoid : an, angular: ar, articular: b.o, basioccipital : 

 d, dentary : e.o, exoccipital : eu, aperture of Eustachian tube : f.m, 

 foramen magnum : fr, frontal: i.o.s, inferorbital septum : ju, jugal : 

 h, lacrymal : Ib.s, lambdoidal suture : m.eth, mesethmoid : mx, maxilla : 

 mx.p, maxillo-palatine process : na, na', na", nasal : o.c, occipital 

 condyle : or fr, orbital plate of frontal : /#, parietal : pa.s, para- 

 sphenoid : //, palatine : /. mx, premaxilla : //, pterygoid : qu, quadrate : 

 s.an, supra-angular : s.o, supraoccipital : sq, squamosal : ty, tympanic 

 cavity : II XII, foramina for cerebral nerves. 



