PLATE LXXVI. 



Orthoceras lcxum. 



Page 244. 

 See Plates 35, 77, 78, 78 B. 81, 112. 



Fig. 1. A small septate fragment possessing the usual charactei-s of the species. The specimen shows a 

 longitudinal raised line along the chambei-s, indicating the position of the ventral side, not 

 represented in the figui-e. ClarksviUe, N. Y. 



Orthoceras cinqulcm. 



Page 240. 

 V\g, 2. Pragfment of the largest individual observed, venti-al side, showing the regular horizontal margins 



of the septa, and the banded or zoned appearance, caused by the solution of the produced 



septal margins. A longitudinal raised line on the specimen is not represented in the ligui-e. 



/Schoharie, N. T. , 



Fig. 3. Dorsal view of a smaller individual. The specimen is much flattened and weathered on the dorsal 



side. The ventral side presents all the distinguishing characters of figure 2. Schoharie, N. Y. 



Orthoceras pluctcm. 



P.igc -239. 

 Fig. 4. A specimen preserving a portion of the chamber of habitation, and fifteen chambers. 

 Fig. 5. A fragment preserving a poi-tion of the chamber of habitation, with twelve of the chambers. The 



lower portion, consisting of seven chambei's. is of 0. hixum, and has been artificially attached 



to the original specimen, escaping observation till the phite had been completed. 

 Fig. 6. Longitudinal section of specimen, fig. 5, showing the depth of the chambers, and convexity of the 



septa. No traces of the si ph uncle are presei'ved. 

 Fig. 7. A septum from specimen, fig. 4, showing the position of the siphuncle. A small areola around the 



siphon is not i-epresented. 



4. 



f 





