C@LosrIRA PLANO-CONVEXA, Hall. 
Fig. 15. The interior of a brachial valve; showing the form of the cardinal 
process and the thickened median ridge. x 2. 
Figs. 16, 17. Dorsal and profile views of an average example. 
Clinton group. Hamilton, Ontario. 
LEPTOCQCSLIA, Hatt. 
Page 803. 
LEPTOC@LIA FLABELLITES, Conrad. 
Figs. 18, 19, 20. Ventral, dorsal and profile views of an average example. 
Fig. 21. The interior of a pedicle-valve; showing the teeth and muscular 
impressions. 
Fig. 22. The interior of a brachial valve; showing the cardinal process, dental 
sockets and muscular area. 
Oriskany sandstone. Cumberland, Maryland. 
Leproce@tia Frmpriata, Hall. 
Fig. 23. Dorsal view of an average specimen. X 2. 
Fig. 24, The interior of a pedicle-valve; showing the teeth and muscular area. 
x 2. 
Fig. 25. The interior of a brachial valve; showing the articulating apparatus. 
x 2. 
Fig, 26. Cardinal view of a brachial valve; showing the elevation of the car- 
dinal process and dental sockets. x 2. 
Fig. 27. Profile view of a brachial valve; showing the elevation of the crura. 
S< 8h 
Oriskany sandstone. Cumberland, Maryland. 
VITULINA, Hatt. 
Page 804. 
Virvtina pustuLosa, Hall. 
Fig. 28. The exterior of a pedicle-valve. x 3. 
Fig. 29. Similar view of a brachial valve. x 3. 
Fig. 30. Profile of conjoined valves. » 3. 
Fig. 31. Cardinal view of conjoined valves; showing the area on each valve, 
the open delthyrium and the cardinal process. x 3. 
Fig. 32. The interior of a pedicle-valve. x 3. 
Fig. 83. An internal cast of the pedicle-valve; showing the muscular area, 
x 3. 
Hamilton group. Western New York. 
231 
