PLATE CXIII— Continued. 
Fig. 21. A fragment of another individual showing nearly the same characters as the preceding. In this 
example the air-chambers include several annulations, and are much deeper than in the smooth 
portion of the tube. 
The specimens of this species here figured are from the sandstones of the Upper Chemung 
group, at Warren, Pa. 
ORTHOCERAS CiELAMEN. 
Page 298. 
See Plates 42, 43, 82. 
A fragment preserving portions of the test, and showing the natural form of the tube and characters 
of the annulations. 
A septum of another individual enlarged two diameters, showing the transverse section of the tube 
and the position of the siphuncle, with the small raised areola around its insertion, and the 
radiating vascular markings extending to the margin of the septum. Hamilton group. Mora¬ 
via, near Cayuga lake, N. Y. 
Orthoceras lima. 
Page 303. 
Fig. 24. A fragment showing the gradually enlarging tube, and the numerous sharp annulations ornamenting 
its surface. Hamilton group. Cazenovia, N. Y. 
Fig. 25. An enlargement of a portion of the surface of the preceding, showing the character of the annula¬ 
tions and the longitudinal stria, interrupted by the lines of growth between the annulations. 
Fig. 22. 
Fig. 23. 
