: Dorsal view of an int 

 Ventral view of the t 

 Punctured external s 



Fig. 2. Chonetks Verx 

 2, a. Ventral valv 



2, b. Outline side 

 2,c. Enlargement 



Fig. 3. Spirifer 



3, a. Ventral 



. Ventral view. 

 Portion of granulated surface magnified. 



