EXPLANATION OF PLATE L. 



Page 



t 'IQ . 1 . Bellerophon crassus. 151 



la View of aperture. 

 Ib . Side aspect . 



Carboniferous, Upper Coal Measures. 



FIG . 2 . BelleropJion percarinatus 15S 



2a. Dorsal aspect. 



2b . A pertural view . 



2c. Same of another individual. . 



2<1. Doreal aspect. 



2e. Side view. 



2f. Same of another example. 



Carboniferous, Coal Measures. 



FIG 3. Bellerophon bilabiatus 147 



Dorsal aspect. (Keyes collection.) 

 Carboniferous, Burlington limestone. 



FIG. 4 . Bellerophon nodocarinatus 152 



4a. Side view. 



4b . View of aperture . 



4c Dorsal aspect . 



Carboniferous, Coal Measures. 



FIG. 5. Bellerophon urii 149 



5 a Dorsal aspect. 



5b. Side view. 



5c. View of aperture . 



Carboniferous, Coal Measures . 



FIG. 6. Bellerophon panneu* 147 



Dorsal aspect. (Keyes collection.) 

 Carboniferous, Burlington limestone. 



FIG 7 Bellerophon bellus 14S 



Dorsal aspect of type. (Keyes collection.) 

 Carboniferous, Upper Coal Measures. 



