202 NORTH STAFFORDSHIRE COAL FOSSILS. 



order. The occurrence of marine fossils in the upper 

 measures, in the roof of two thin seams of coal and in no 

 other, is one of the most curious problems which have come 

 under our notice. 



BRACHIOPODA. 



Athyris, sp. : very rare : in the roof of the Bay coal, 

 Longton. 



Chonetes, sp. : rare : in a bed of grey rock above the Gin 

 mine. 



Disdna nitida (Phil.) : roof of Bay coal, Gin mine ; Lower 

 Coal Measures. 



Lingula mytiloides (Sow. Min. Conch, t. 19) : roof of Bay 

 coal, Gin mine ; Lower Coal Measures ; Churnet 

 Valley. 



Lingula squamiformis (Phil.) : roof of Bay coal and Gin 

 mine ; Lower Coal Measures ; Churnet Valley. 



j sp. : rare : roof of Bay coal, Longton. 

 ProdmtuSj sp. : rare : roof of Bay coal, Longton. 

 Spirifer Urii : rare : roof of Bay coal, Longton. 



Lamellibranchiata. This class of the Mollusca is divided 

 into two groups, Monomyaria and Dimyaria. Of the first 

 named group, Aviculopecten is the most abundant. In the lower 

 measures, especially in the shale of the Stinking coal, great 

 quantities of this shell occur. It is also found in the Gold- 



