^uarMvmtO 



PLATE GXlll— Continued. 



Tig. tl. 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 WarrcTi, Pa. 



Orthocera.8 cjelamen. 



Page 298. 



See Plates 42, 43, 82. 



Fig. 22. A fragment preserving portions of the test, and showing the natural form of the tube and characters 



of the annulations. 

 Fig. S3. A septum of another individual enlarged two diameters, showing the transverse section of the tabs 

 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, Tiear Cayuga lake, N. Y. 



Obthoceras lima. 



P«ge»03. 

 Fig. 34. A fragment showing the gradually enlarging tube, and the numerous sharp annulations ornamenting 



its surface. Hamilton group. Caaenovia, N. T. 

 Fig. 35. An enlargement of a portion of the surface of the preceding, showing the character of the annul»> 



tions and the longitudinal striae, inteiTupted by the lines of growth between the annulations. 



