PLATE XXXIII 



PAGE 



Figs. 1-6. MODIOMORPHA SUBALATA (Conrad) 268 



I, 2. Right and left valves. 



3. Right valve. 



4. Left valve of small specimen. X 2. 



5. Probably right valve of young specimen. X 2. 



6. An imperfect right valve. 



Romney formation, Hamilton member, Evitts Creek. 



Fig. 7. MODIOMORPHA MYTILOIDES (Conrad) (?) 269 



Left valve from which umbonal region is broken. 



Romney formation, Hamilton member, Evitts Creek. 



Figs. 8-10. MODIOMORPHA MYTILOIDES (Conrad) 269 



8, 9. Right and left valves. 

 10. Young specimen showing both valves. 

 Hamilton formation, New York. 



Figs. 11-13. GONIOPHORA HAMILTON ENSIS Hall 271 



II. Partly exfoliated right valve, showing sharp umbonal ridge. Rom- 



ney formation, Hamilton member, Hancock-Harrisonville Road, 

 about 2 miles north of Hancock. 

 12, 13. Right and left valves. Hamilton formation, New York. 



Figs. 14-16. PHOLADELXA RADIATA (Conrad) 272 



14, 15. Right and left valves. Hancock-Harrisonville Road, about 2 



miles north of Hancock. 

 16. Cardinal view of a specimen. Cumberland. 



Romney formation, Hamilton member (fig. 16, after Hall). 



116 



