PLATE 37. 



Fig. 1. 523. 1. Stromatopora concentrica. ( Pag. 136.) 



1 a. The surface of a small hemispheric mass, showing the edges of the thin laniinre whicli are unequally 



weathered. 

 1 b. A magnified portion of the same surface, showing the circular ends of the cylindrical tubes. 

 1 c. A magnified portion, showing the weathered edges of successive laminaj which are indented by the cells, 



giving them the appearance of being arranged in concentric lines. 

 1 d. A transverse section of a small mass. 

 1 e. A magnified portion of the same. 



1 /. A larger mass, showing the effects of weathering upon the thin concentric lamina. 

 1 g. The base of the same specimen, showing several centres of growth. 



