30 



Fossil Fishes. 



oooa 

 OC.OO 



ooao 



88 





»*& 



P 



BR 



Fig. 65. — Portions of Pvcnodonts. a, transverse section of jaws, showing the two 

 halves of the mandibular dentition opposing the vomerine teeth; b, dentition of 

 Microdon; c, dentition of Ccelodus; d, portion of vertebral column of Ccelodus, 

 showing persistent noctochord (shaded), and the expanded bases of the arches; 

 e, the same of Pycnodus : /, inner view of scales, showing mode of interlocking by 

 pegs and sockets, which are continued as longitudinal ribs. 



Fio. 66.— Upper dentition of Ccelodus ellipticus, Gault, Folkestone. 



Suborder IV. — Amioidei. 



Wall-case ^he Amioidei are represented by the Amia, or " Bow-fin," of the 



No. 15. United States fresh-waters. 



Table-cases, In "Wall-case 15, and Table-cases 46-48, are arranged 

 Nos. 46 to 48. 



