THE PIGEON. 



189 



qu 



?" ^ i fa 



,,LM or J'' fr 



eth < \ _=L / /s 



7l(t lc 



o.c. 



no.* 



nmas 



S.O.JL 



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 

 (nat. size). 



The cartilaginous parts are distinguished by dotting. 



aLs, 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, inierorbital septum : ju, jngal : 

 Ic, 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 : p.mx, premaxilla : //, pterygoid : qu, quadrate : 

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

 cavity : II- XII, foramina for cerebral nerves. 



