86 



Morphology of the Fins 



todus, and the Batrachians as represented by the Ganocephala, 

 Salamanders, and Salamander-like animals. 



"2. The articulation of the anterior member with the shoul- 

 der-girdle forms the most obvious and determinable point for 

 comparison in the representatives of the respective classes. 



The Girdle in Dipnoans. ' ' The proximal element of the anterior 



FIG. 71. FIG. 72. 



FIG. 71. Shoulder-girdle of Amia calva (Linnseus). 

 FIG. 72. Shoulder-girdle of a Sea Catfish, Selenaspis dowi. 



limb in the Dipnoi has almost by common consent been regarded 

 as homologous with the humerus of the higher vertebrates. 



" The humerus of Urodele Batrachians, as well as the extinct 

 Ganocephala and Labyrinthodontia, is articulated chiefly with 

 the coracoid. Therefore the element of the shoulder-girdle with 

 which the humerus of the Dipnoi is articulated must also be 

 regarded as the coracoid (subject to the proviso hereinafter 

 stated), unless some specific evidence can be shown to the con- 

 trary. No such evidence has been produced. 



" The scapula in the Urodele and other Batrachians is entirely 

 or almost wholly excluded from the glenoid foramen, and above 



