4 66 



MANUAL OF ZOOLOGY 



istic parts of the bird's skeleton. It is a broad plate of bone 

 produced ventrally, in the sagittal plane, into a deep keel or 

 carina sterni (car) , formed, in the young bird, from a separate 

 centre of ossification. The posterior border of the sternum 

 presents two pairs of notches, covered, in the recent state, 



r *% l t \ 



, i.o.s wfr p 

 n.etlh \ I ''i 



S.0.71 €LTb 



-,. 270. — Columba livia. Skull of young specimen. A , dorsal ; B, ventral; C, 

 left side. al. s, alisphenoid; a?i, angular; ar, articular; b o, basi-occipital ; 

 d. dentary; e. 0, ex-occipital; en, aperture of Eustachian tube;/", m, foramen 

 magnum; fr, frontal; /. o. s, inter-nrbital septum; j?t, jugal ; tc, lachrymal ; lb. s, 

 lambdoidal suture; m. eth, mesethmoid; ntx t maxilla; mx.p, maxillo-palatine 

 process; na, na' , na" , nasal; o. c, occipital condyle; or. fr, orbital plate ot 

 frontal; pa, parietal; pa. s, parasphenoid (rostrum); pi, palatine; p. mx, pre- 

 maxilla; pt, pterygoid; qu, quadrate; .r. a?i, supra-angular; s. o, supra-occipital^ 

 sq, squamosal; ty, tympanic cavity; II. — XII, foramina for cerebral nerves. 

 (From Parker's Zootomy,') 



