PALEONTOLOGY. 



163 



Orthis 



Pentamerus 



Productus 



Eetzia 

 Rhynconella 



lenticularis 



lunata 



orbicularis 



resupinata 



reversa 



rustica 



vespertilio 



galeatus 



globosus 

 Knightii 



lens 



U. Cambrian. Lingula flags. 

 U. Silurian. Ludlow. 



". 



Carboniferous. 



Silurian. U. Llandovery. 

 U. Silurian. Wenlock. 

 L. Silurian. Llandeilo. 

 U. Silurian. Wenlock and 



Ludlow. 



Silurian. U. Llandovery. 

 Wenlock and 



Ludlow. 

 Silurian. U. Llandovery. 



lirata 



U. Llandovery. 

 Silurian. I 



