PLATE L. 
Cyrtoceras Jason. 
Page 381. 
Fig. 1. A large fragment, preserving the grand chamber and a portion of the air-chambers, showing the 
curvature of the tube and the depth of the air-chambers. Toward the apex there is a sinus in 
several of the septal sutures, produced by the spinous processes of the test. 
Fig. 2. A fragment of a large individual, preserving the natural form of the shell, showing the hexangular 
form of the tube and the sinus of the ornaments on the ventral side. Several fragments of the 
test are preserved, with the lamellose surface-markings. The internal mould retains the 
impression of the furrows and striae of the crenulations, with the bases of the spines on 
the obtuse angles of the tube. 
The specimens of this species here illustrated are from the Schoharie grit, Schoharie, JST. F. 
