PLEUROPTERYGII. 



31 



FIG. 24. 



Cludoselache fyleri; restoration by B. Dean, from lateral and ventral aspects, 

 one-seventh nat. size. U. Devonian ; Ohio. Since this restoration was 

 made, a low anterior dorsal fin has been discovered. 



Fio. 25. 



Cladoselache ; caudal fin, about one-half nat. size. U. Devonian; Ohio. 

 D, fin-membrane ; N, neural arches of upturned lobe ; B, endoskeletal 

 cartilaginous rajs. (After Dean.) 



