7,8. 
9,11. 
12. 
13, 14. 
15, 16. 
17. 
18. 
19-21. 
22, 23, 25. 
24, 
26. 
330 
. Back, front, and summit views of a specimen from Mullica Hill. 
EXPLANATION OF PLATE XVI. 
GYRODES PETROSA Morton (p. 127). 
Am. Mus. Nat. Hist., 
New York City, 
. Summit view of a cast from Crosswicks Creek. Columbia College. 
GYRODES CRENATA Conrad (p. 126). 
. Two views of the type specimen from the Acad. Nat. Sci. Phila. 
GYRODES ALTISPIRA Gabb (p. 128). 
Front and back views of a cast from Mullica Hill in the Am. Mus. Nat. Hist., 
York City. 
New 
GYRODES OBTUSIVOLVA Gabb:(p. 129). 
Views of different specimens from Upper Freehold. | 
View of another cast in the collection of the Am. Mus. Nat. Hist., New York City, from 
New Egypt, New Jersey. . 
LUNATIA TIALLI Gabb. (p. 130). 
Two views of a specimen from Mullica Hill in the Acad. Nat. Sci. Phila. 
Similar views of a cast from the same place in the Am. Mus, Nat. Hist., New York City. 
AMAUROPSIS PUNCTATA Gabb (¢p. 132). 
View of the type specimen. Acad. Nat. Sci. Phila. 
Enlargement of the surface. 
Views of different individuals showing but slight diversity in form. 
AMAUROPSIS MEEKANA Whit. (p. 181). 
Views of different specimens showing a slight difference in form. Fig.22 enlarged to two 
diameters. 
Enlargement of the surface. 
AMAUROPSIS PALUDINZFORMIS H. M. (pp. 131, 132). 
Enlarged view of the type of this species for comparison, two diameters. 
Hist., New York City. 
Am. Mus. Nat. 
