PLATE XVIII 



PAGE 



Fig. 22. Tamiosoma gkegaiua. 61 



22(t. View of Mr. Conrad's original specimen, showing the internal 

 plates. 



22 b. End view of the same, showing the thickness of the walls and the 

 surface of the septa. 



22 c. Magnified view of a section of the walls and of the origins of the 

 transverse septa. 



22 d. Magnified view of a portion of the internal surface with the remains 

 of septa. 



22 e. Section of the wall of Radiolites squamosa, to exhibit the simi- 

 larity of the columnar structure. 



