PLATE XLYI. 
Gomphoceras Conradi. 
Page 348. 
Fig-. 1. Lateral view of a small individual, showing the endogastric curvature of the tube, the furrows of 
the crenulations at the base of the chamber of habitation, and the concentric strise of the test 
over the septate portion. Goniatite limestone. Manlius, N. Y. 
Fig. 2. Ventral view of the preceding, showing the small aperture and the form of the shell. 
Fig. 3. Ventral view of the chamber of habitation of a larger individual, showing the constriction of ti.e 
tube near the aperture, and the narrow, crenulated zone at the base. Goniatite limestone. 
Manlius, N. Y. 
Gomphoceras beta. 
, Page 326. 
Fig. 4. An individual considerably compressed, preserving the greater portion of the chamber of habitation 
and air-chambers. The curvature of the sutures is due to compression. Schoharie grit. 
Schoharie, N. Y. 
Fig. 5. Ventral view of the chambered portion of another individual, showing the impression left by the 
removal of the siphuncle in the process of weathering. Schoharie grit. Schoharie, N. Y. 
Gomphoceras oviforme. 
Page 344. 
See Plates 45, 94. 
Fig. 6. A small, globose individual, showing the general form of specimens of this size. The epidermal 
layer of the test has been exfoliated at the apical portion of the tube, showing the markings 
and structure of the nacreous layer. Goniatite limestone. Schoharie, N. Y. 
Fig. 7. An enlargement of the surface of the apical portion of the preceding, showing the characters of the 
nacreous layer of the test. 
Gomphoceras absens. 
Page 324. 
Fig. 8. Lateral view of a fragment showing the curvature of the tube. Schoharie grit. Schoharie, N. Y. 
Fig. 9. Ventral view of the preceding, showing the enlargement of the tube, the regularity of the air-cham¬ 
bers, and the impression of the siphuncle, which has been removed in the process of weathering. 
PHRAGMOCERAS ? EXPANSUM. 
Figs. 10, 10. This specimen is erroneously figured on this plate as from the Hamilton, but belonging to the 
Coralline limestone of the Niagara group. See Addenda for explanation. 
The representation of the siphuncle is incorrect; the specimen showsjt to be on the concave 
side of the tube. 
Cyrtoceras alternatum. 
Page 365. 
Fig. 12. Ventral view, showing the undulations of the tube and the siphuncle, as exposed in the process of 
weathering. The undulations and rounded nodes on the tube are not fully represented in the 
figure. Goniatite limestone. Schoharie, N. Y. 
Fig. 13. Lateral view of the preceding, showing the curvature of the tube. 
Gomphoceras clavatum. 
Page 323. 
See Plate 93. 
Fig. 14. Lateral view, showing the endogastric curvature of the tube and the comparative convexity of the 
dorsal and ventral sides. Schoharie grit. Albany county, N. Y. 
Fig. 15. A view of the convexo-dorsal side of the preceding, showing the form of the tube and the depth of 
the air-chambers. 
