FIGS. 1. 
13. 
14. 
15, 16. 
17, 18. 
19, 20. 
21, 22. 
23-25. 
26, 27. 
28. 
29. 
30. 
336 
EXPLANATION OF PLATE XIX. 
OBELISCUS CONELLUS Whitf. (p. 151). 
View of the front side of the specimen described, greatly enlarged. Acad. Nat. Sci. Phila. 
LEIOSTRACA CRETACEA Conrad (p. 1o0). 
. Views of three specimens showing the features described, enlarged four, five, and three 
diameters respectively. 
. A still further enlargement of the aperture from another shell. Acad. Nat. Sci. Phila, 
HELCION ? TENTORIUM Morton (p. 153). 
Lateral and vertical views of the type, enlarged. Acad. Nat. Sci. Phila. 
. Further enlargement of the marginal striz. 
ACTON CRETACEA Gabb (p. 158). 
Two views of a cast which shows no spiral striz. 
. Two views of another cast showing spiral strie. Acad. Nat. Sci. Phila. 
Acton GaBBana Whitf. (p. 156). 
Front view of one of Mr. Gabb’s types of A. biplicata. See Figs. 23-25. 
ACTON SUBOVOIDES Whitf. (p. 155). 
Front view of the specimen marked ‘“‘ type of A. ovoides Gabb.” 
Two views of a second specimen. Acad. Nat. Sci. Phila. 
ACTON FORBESIANA Whitf. (p. 157). 
Two views of a cast of the species. ; 
Enlargements to two diameters of Fig. 17 and another specimen, showing the spiral lines. 
Two views of an individual from Mullica Hill. 
ACTZON GABBANA Whitf. (p. 156). 
Further illustrations of this species to show the aperture, etc. 
GLOBICONCHA CURTA Gabb (p. 160). 
Front and lateral views of a cast of this species from Bell County, Texas. 
CINULIA (OLIGOPLYCHIA) NATICOIDES Gabb (p. 161). 
View of a specimen, natural size, from the collection at Columbia College. Monmouth 
County, New Jersey. 
Enlargement of the front of the same. . 
View of another cast showing the cavity of the ridge. Crosswicks Creek, New Jersey. 
