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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



[Mar. 6, 



given in the following table, the Mollusca and Polyzoa of the Lower 

 Limestone being placed in juxtaposition for the sake of easy 

 comparison : — 



Compact Limestone (Durham). 



Dentalina Permiana. 

 Miliola pusilla. 

 Kirkbya Permiana. 

 Retepora Ehrenbergi. 

 Acanthocladia anceps. 

 Fenestella retiformis. 

 Stenopora Mackrothi, 

 Synocladia virgulacea. 



Lingula Credneri. 

 Disciha Konincki. 

 Productus horridus. 

 Strophalosia lamellosa. 



Goldfussi. 



Streptorhynchus pelargonatus. 

 Spii'ifera alata. 

 Caraarophoria crumena. 



globulina. 



Spii'ifera Urii. 

 Terebratula elongata, 

 Monotis speluncaria, 

 Gervillia antiqua. 



Axinus dubius. 

 Myoconcha costata. 

 Leda speluncaria. 

 Astarte Vallisnieriana, 



Tunstallensis. 



Solemya biarmica. 



norma lis. 



Pecten pusillns. 

 Myacites lunulata. 



Pleurotomaria Yernenili. 



Lower Limestone ( South York- 

 shire )*. 



# K. Permiana. 



# Retepora Ehrenbergi. 



* Acanthocladia anceps. 



* Stenopora Mackrothi. 

 Thamniscus dubius. 



Nautilus Freieslebeni. 

 t Platysomus striatus. 



* Terebratula elongata. 



* Monotis speluncaria. 



* Gervillia antiqua. 



* keratophaga, 



* Axinus dubius. 



* Myoconcha costata. 



* Leda speluncaria, 



Myalina Hausmanni. 



* Cardiomorpha Pallasi. 



* Macrodon striatus. 



Turbo helicinus. 

 Rissoa Leighi. 

 Turrit. Altenburgensis. 



* Chemnitzia Roessleri. 

 Natica minima, 

 Chiton Loftusianus. 



* Dentalium Sorbyi. 



* Straparollus Permianus. 



* Nautilus Freieslebeni. 



It is thus seen that 11 species are common to both groups, 

 amongst which are the Cephalopod, 5 Conchifers, the Brachiopod, 

 3 Polyzoans, and 1 Entomostracan. "When we consider the nearness 

 of the two areas — their distance apart being only about 80 miles — 



* The species marked with asterisks occur in the Zechstein. 

 t The list of species from the Compact Limestone is based upon the researches 

 of Prof. King, Mr. Howse, Mr. Manson, and Mr. Parker. 



