THE PIGEON. 



189 



B 



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

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

 (nat. size). 



The cartilaginous parts are distinguished by dotting. 



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

 </, dentary : e.o, exoccipital : eu, aperture of Eustachian tube : f-tn, 

 foramen magnum : fr, frontal : i.o.s, in*erorbital septum : jit, jugal : 

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

 mx.p, maxillo-palatine process : na, na' , no.", nasal : o.c, occipital 

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

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

 s.art, supra-angnlar : s.o, supraoccipital : sq, squamosal : ty, tympanic 

 cavity : II^-XII, foramina for cerebral nerves. 



