PLATE 86. 
Fig. 1. 373. 27. ORTHOCERAS CORALLIFERUM. (Pag. 312.) 
1 a. A small fragment from the altered shales near Waterford, Saratoga county. The septa are represented too 
distant in the figure. A portion of the coral covering the surface is magnified in 1 d. 
1c. A fragment from the green shales of Lewis county. 
1d. A fragment from the sandstone of the Hudson-river group. 
Fig. 2. 374, 28. ORTHOCERAS LAMELLOSUM. (Pag. 312.) 
2b, c. Fragments near the smaller extremity; the septa being indistinctly preserved. 
2d. A fragment showing the comparative distance of the septa, in which it varies slightly from 2 c. 
2 e. Section of the last, showing the position of the siphuncle. 
Fig.2 a, 375. 2. ORMocERAS CREBRISEPTUM. (Pag. 313.) 
A fragment of this species, the siphuncle being distinctly moniliform. 
