PLATE LXXVI. 
ORTHOOERAS LtiXTJM. 
Page 244. 
See Plates 35, 77, 78, 78 B, 81, 112. 
Fig. 1. A small septate fragment possessing the usual characters of the species. The specimen shows a 
longitudinal raised line along the chambers, indicating the position of the ventral side, not 
represented in the figure. Clarksville, IV. T. 
Orthooeras cingulum. 
Page 240; 
Fig. 2. Fragment of the largest individual observed, ventral 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 figure. 
Schoharie, IV- Y. 
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. 
Orthooeras eluctum. 
Page 239. 
Fig. 4. A specimen preserving a portion of the chamber of habitation, and fifteen chambers. 
Fig. 5. A fragment preserving a portion of the chamber of habitation, with twelve of the chambers. The 
lower portion, consisting of seven chambers, is of 0. Inxum, and has been artificially attached 
to the original specimen, escaping observation till the plate 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 siphuncle are preserved. 
Fig. 7. A septum from specimen, fig. 4, showing the position of the siphuncle. A small areola around the 
siphon is not represented. 
