106 TRANSCENDENTAL ANATOMY IN ENGLAND 



Cranial Vertebra. 1 (After Owen, 1848, p. 165.) 



Owen's reasons for considering the pectoral girdle and the 

 fore-limb part of the occipital vertebra are as follows. In 

 fish the pectoral girdle is slung to the skull by means of the 

 post-temporal bone (supra-scapula, according to Owen) 

 which abuts on the occipital arch. In Lcpidosircn, whose 

 skeleton resembles the archetype in many ways, the pectoral 

 girdle is likewise attached to the occipital segment. 



In most other Vertebrates the pectoral girdle has shifted 

 backwards along the vertebral column, by a "metastasis" 

 (Geoffroy) similar to that by which the pelvic fins in many 

 fish have shifted up close to the pectoral girdle. The scapula 

 (with supra-scapula) is the pleurapophysis, the coracoid the 

 h;umapophysis, of the occipital vertebra. The clavicle is 

 homologised with the slender bone in fish now known as 

 the post-clavicle, which shows a connection with the first 

 or atlas vertebra of the vertebral column, forming, according 

 to Owen, the h;emapophysis of the atlas. Owen considers 

 it no objection to this view that in other Vertebrates the 



1 Owen introduced most of the names of bones now current. 



