PLATE XI. 
Pleurotomaria rugulata. 
Page 75. 
Figs. 1-3. Three views of a specimen having the shell denuded ; fig. 2 shows the plicae near the lip. 
Figs. 4, 5. The spire of another specimen and apertural view of the same. 
Fig. 6. Enlargement to two diameters of a specimen faith high spire and obliquely compressed volutions. 
The substance of the shell is preserved showing the surface-markings and spiral band. 
Fig. 7. Enlargement to two diameters of a specimen with more ventricose volutions and shorter spire, pre¬ 
serving the spire and having a proportionally wider band. 
Pleurotomaria Itts. 
Page 76. 
Fig. 8. A large specimen almost denuded of shell, but indicating surface-markings on the upper volutions 
and remains of the spiral band on the last volution. From near Bellona, N. Y. 
Figs. 9, 10. Two views of an internal cast. From Cumberland, Md. 
Figs. 11, 12. Two views of a partial cast retaining traces of the surface characters toward the aperture. 
From western New York. 
Fig. 13. A cast showing only the remains of the spiral band. From Canandaigua Lake, N. Y. 
Fig. 14. A specimen preserving the surface characters in remarkable perfection. From Pratt’s Falls, near 
Pompey, Onondaga county, N. Y. 
Fig. 15. A large, well-preserved specimen retaining the surface characters. From York, Livingston 
county, N. Y. 
Fig. 16. Enlargement of a part of the body-volution of the specimen figure 11. 
Fig. 17. Enlargement of a part of the body-volution of fig. 15, showing some differences in the strength and 
character of the markings from those of fig. 16. 
Pleurotomaria capillaria. 
Page 77. 
Figs. 18, 19. A specimen enlarged to two diameters, of usual form and size. From the Hamilton group, 
Madison county, N. Y. 
Fig. 20. Enlargement (two diameters) of a specimen, preserving the upper volutions, and showing surface 
chai'acters different from the preceding. From the soft shales of the Hamilton group, Norton’s 
Landing, east side of Cayug-a Lake, N. Y. 
Fig. 21. Enlargement to two diameters of a specimen which differs in surface characters from the preceding. 
From the same locality. 
Pleurotomaria Ella. 
Page 72. 
Figs. 22-25 The opposite sides, summit and basal views of a specimen which exhibits the surface characters 
very perfectly. It has probably been somewhat compressed vertically, flattening the volutions, 
but not materially altering the form. 
Pleurotomaria filitexta. 
Page 73. 
Fig. 26. The side of a flattened specimen with surface characters very beautifully preserved. The trans- 
verse striae are too coarse in the figure, and the revolving striae should be entirely subor¬ 
dinate. 
Fig. 27. The opposite side of the same specimen, having a part of the outer volution broken away revealing 
the columella and umbilical callus. 
