178 



THE BATH OOLITE PERIOD. 



CHAP. 



Hybodontidce. 

 Hybodus apicalis. 

 dorsalis. 

 grossiconus 

 marginalia. 

 polyprion. 



2 



Dorsal spines and teeth detached, occasionally 

 waterworn. 



Diagram XXXVIII. Stonesfield Fishes Spines. 



I. Hybodus dorsalis. Ag. Oxford Museum. (The denticles below.) 2. Hybodus 

 apicalis. Ag. 3. Nemacanthus brevis. Phil. Oxford Museum. 4. Termination 

 of the spine. 5. The granulated surface. 6. Hybodus marginalis. Ag. 



7. Asteracanthus semisulcatus. Ag. 8. Leptacanthus serratus. Ag. (The denticles 

 above.) 9. Leptacanthus semistriatus. Ag. Oxford Museum. (The denticles below.) 

 10. Pristacanthus securis. Ag. 



These are usually rnesodorsal spines, sometimes worn by attrition, and rarely quite 

 perfect. 



JEdaphodontidce. 



Ganodus Bucklandi. 



Colei. 



curvidens. 



dentatus. 



emarginatus. 

 falcatus. 



neglectus. 



Oweni. 



psittacinus. 



rugulosus. 

 Pycnodontidce. 



Jaws which are minutely denticulated, or else 

 fulfil the functions of teeth. 



Gyrodus perlatus. 

 trigonus. 



Figures i. 3. 7. 8. in Diagram XXXIX. are 

 vomerine teeth of this family. 



