PLATE CV. 
Nautilus magiister. 
Page 422. 
See Plates 62, 107, 108. 
Fig. 1. A fragment, preserving two of the air-chambers near the base of the grand chamber, with one of 
the smaller ones at the distance of half a volution; the impressions of the intervening air- 
chambers and septa being marked upon the adhering matrix, showing the re-entrant character 
of the volutions and the sinus in the septa on the dorsal side. The comparative diameter of the 
two volulions, as presented in the fragment, are about as 65-115. The convex surface of the 
larger air-chamber is flattened and distorted from compression and weathering, which obscures 
the siphuncle : from the same cause the concavity of the dorsal side of the large chambers has 
been partially obliterated, as shown in the outline of the figure. 
The specimen is referred with some hesitation to JV. magisler; but, the proportions of the 
parts are essentially the same as in typical specimens of that species, and it is quite distinct 
from any other form. Lower part of the Hamilton group. Near Leonardsville, Madison 
county, N. Y. 
Nautilus oriens. 
Page 420. 
See Plate 61, 106. 
The ventral side of a compressed and imperfect chamber of habitation, with several air-chambers at the 
base* The shell is partially preserved on one side, showing the transverse lamellose striae, and the impres¬ 
sion of the same on the other side, which is exfoliated, showing numerous plumose, branching Bryozoans 
which have adhered to the inner surface of the shell. From the Marcellus shale. Near Riclmondville , 
Schoharie county, N. Y. 
