234 



Explanation of the Plates. 



Menobranchus lateralis - Plate XVI. 



Abranchus Alleghaniensis -'-,.- Plate XVII. 



Details of organization of A. Alleghaniensis - Plate XVIII. 



Os hyoides and spiracular cartilages, Fig. 1. 



Vertebrae, Fig. 2. 



Upper and side views of the head, Fig. 3, 4. 



Hind foot, Fig. 5. 



