PLATE LIX. 
Trochoceras Clio. 
Page 392. 
See Plate 111. 
Fig - . 1. The upper side of the internal mould of an individual, showing- the depth of the air-chambers, and 
the extent of the grand chamber. The impression of one of the inner volutions is retained, 
showing the surface ornaments. 
Fig. 2. The umbilical side of an individual, showing the diameter of the umbilicus, and the annulations and 
i-evolving strife of the test. The septal sutures are less frequent, and oblique to the annulations. 
Fig. 3. Profile view of the preceding, showing the deflection of the volutions. 
Fig. 4. The concave dorsal side of the chamber of habitation, showing the transverse section of the tube; 
the position of the small siphuncle which is sun-ounded by an obscure areola, and the surface- 
characters on the inner side of the volution. 
Fig. 5. A small individual nearly entire, showing the form of the shell, the number of volutions, and the 
height of the spire. 
Fig. 9. A large individual, showing the 'numerous continuous annulations, and the gradually enlarging- 
tube. The annulations are rounded on the outer volution, and are wanting on the chamber of 
habitation. The specimens of this species are from the Schoharie grit, at Schoharie, N. Y. 
Trochoceras discoideum. 
Page 394. 
Fig. 6. Upper lateral view of a small individual, showing the depressed spire, the enlargement of the tube, 
the linear, transverse, annular nodes, and the revolving strise of the test. 
Fig. 7. The same view of a larger specimen, showing stronger undulations of the tube, with several septa 
near the apex. 
Fig. 8. The umbilical side of an example, showing the rapidly enlarging tube and the broad, shallow 
umbilicus. Schoharie grit. Schoharie, N. Y. 
Trochoceras eugenium. 
Page 396. 
See Plate 58. 
Fig. 10. A view of the upper lateral side of an individual, preserving the grand chamber and a part of the 
septate portion, the whole forming a little more than an entire volution, and showing the outer 
half of the grand chamber produced beyond the inner volution, in a straight tine, and not 
following the curvature 6f the spiral axis. 
Fig. 11. A similar view of a larger individual, showing the gibbous form of the shell and the contraction of 
the tube toward the aperture. Schoharie grit. Schoharie, N. Y. 
