TAB. XVIII. 
Fig. 
1. Marginella eburnea. No. 80, p. 137. 
a. Front view, natural size. 
6. Front view, magnified. 
c. Side view, ditto. 
2. Marginella bifido-plicata. No. 81, p. 139. 
a. Front view of adult shell from Barton, natural size. 
4. Front view of the same, magnified. 
ec. Front view of young shell, from ditto, ditto. 
d. Side view of adult shell, ditto, ditto. 
e. Front view of adult shell, Var. from Alum Bay, nat. size. 
J. Side view of the same, magnified. 
g. Front view of the same, magnified. 
3. Voluta luctatrix. No. 87, p. 147. 
Back view, adult shell. 
4. Marginella gracilis. No. 82, p. 140. 
a. Front view, natural size. 
4. Front view, magnified. 
c. Side view, ditto. 
5. Marginella ovulata. No. 83, p. 141. 
a. Back view, natural size. 
6. Back view, magnified. 
c. Front view, ditto. 
Note.—The posterior extremity of the outer lip is imperfect. 
6. Marginella pusilla. No. 84, p. 143. 
a. Front view, natural size. 
6. Front view, magnified. 
c. Side view, ditto. 
7. Marginella vittata. No. 86, p. 144. 
a. Front view, natural size. 
6. Front view, magnified. 
c. Side view, ditto. 
8. Marginella simplex. No. 85, p. 143. 
a. Back view, natural size. 
6. Front view, magnified. 
c. Side view, ditto. 
