EXPLANATION OF PLATE III. 



Actinoceras hardmani, Etli. Fil. 



Pig. 1. Lateral view showing the septa, and beaded siphnncle at the 

 distal or younger end. 



,, 2. Beaded siphnncle — X 2. 



„ 3. Section of the siphnncle showing involutions of the membrane — 

 X 3. 



„ 4. Pyriform involutions at the proximal or older end of the shell, 

 seen in weathered section — X 5. 



„ 5. Involutions and intermediate ridges at the proximal or older end 

 of the shell, seen in partially oblique weathered section — X 5. 



