EXPLANATION OF PLATE XX. 
AVELLANA BULLATA Morton (p. 163). 
Fics. 1,4. Views of two different specimens, apparently both used by Dr. Morton. Acad. Nat. Sci., 
Phila. 
CINULIA OVOIDEA Gabb (p. 162). 
5,6. Two views of Mr. Gabb’s type specimen. 
BuLLA Morront Lyell & Forbes (p. 165). 
7,8. Front and back views of a very large specimen from Crosswicks, in the Columbia College 
collection. 
9. View of a smaller specimen. Collection Acad. Nat. Sci., Phila. 
CYLICHNA RECTA Gabb (p. 164). 
10,11. Two views of the type specimen enlarged two diameters. 
DENTALIUM (FALCULA) FALCATUM Conrad (p. 169). 
12,14. View of small much curved specimen, all casts. 
15-17. Views of the larger portion of three individual casts. 
12. Portion of a partial cast. looking on the back and showing striw# of growth. Acad. Nat. 
Sci. Phila. 
DENTALIUM SUBARCUATUM Conrad (p. 166). 
19. View of a crushed shell from Haddonfield, New Jersey. 
20. View of a shell showing the curvature. 
21,22. Opposite sides of casts showing the internal features described. 
23,24. Enlargement of the surface of Fig. 19, and transverse section of the same. Acad. Nat. 
Sci., Phila. 
SERPULA (DIPLOCONCHA) CRETACEA Conrad ? (p-170). 
25. View of the specimen described showing the general features, 
