PLATE XV 



PAGE 



Figs. 1-3. CAMABOTCECHIA PROLIFICA Hall 173 



1. Exfoliated ventral valve. X 1%. Right bank of Potomac, about 4 



miles south of Cumberland. Romney formation, Hamilton 

 member. 



2. Ventral valve of an unusually large specimen. 



3. Interior of dorsal valve. 



Hamilton formation, New York. 



Fig. 4. CAMAROTCECHIA SAPPHO Hall 174 



Interior of ventral valve. Romney formation, Hamilton member. 



Fig. 5. CAMAROTCECHIA sp 175 



Interior of ventral valve. X l 1 ^. Flintstone Creek in Gilpin. Romney 

 formation, Hamilton member. 



Figs. 6-8. LIORHYNCHTJS LIMITARE (Vanuxem) 175 



6, 7. Crushed and broken dorsal valves. X 1%. 21st Bridge. 

 8. Young specimen crushed. X 3. Same locality. 

 Romney formation, Marcellus member. 



Figs. 9-12. LIORHYXCHUS LAURA (Billings) 177 



9. Somewhat distorted and crushed exfoliated dorsal valve. X 1%. 

 Williams Road near church, Sy 2 miles southeast of Cumberland. 



10. Interior of dorsal valve. X l 1 ^. Williams Road near church, 3^5 



miles southeast of Cumberland. 



Romney formation, Hamilton member. 



11. Dorsal valve of typical specimen. 



12. Cardinal view. 



Hamilton formation, New York. 



Figs. 13-17. LIORHYNCHUS CF. MYSIA 178 



13-15. Dorsal, ventral and side view of shell of usual size. 



16. Dorsal view of larger specimen with duplicate plications. 



17. Dorsal view of large individual. 



Marcellus formation, New York. 



Figs. 18-23. EUNELLA LINCKL^ENI Hall 179 



18. Interior of ventral valve, distorted by pressure. Iron Bridge over 



Town Creek northeast of Oldtown. 



19. Interior of dorsal valve of same specimen. 



20. Interior of dorsal valve. Road east of Pine Hill, about 4 miles 



north of Oldtown. 



21. Partly exfoliated ventral valve of same specimen. 



22. Enlargement showing shell structure of same. X about 20. 



Romney formation, Hamilton member. 



23. Brachial loop. Hamilton formation, New York. 



