FRESH-WATER FOSSILS OF COS. 201 

 In the fresh-water strata, against which the 

 marine newer pliocene beds abut unconformably, 

 there are also numerous and well-preserved 



Tertiaries of Cos . a, freshwater beds, a, b, c successive series of fossiliferous 

 zones, b, Marine Newer Pliocene beds. 



fossils : shells of Paludina, Neritina, Melanopsis, 

 Melania, Valvata, Unio, Cyclas, and Planorbis, 

 occur, marking the nature of the deposit. With 

 them, teeth of a Cyprinus were found, also leaves 

 and stems of plants, and in the uppermost 

 stratum, shells of the common cockle. 



The great interest of this formation depends 

 on certain appearances presented by the mollusca 

 of the genera Paludina, Melanopsis, and Neritina, 

 found in great quantities in several parts of it. 

 They occur distributed in distinct horizons, 

 throughout the vertical thickness of the section. 

 These horizons form three series, each of which 

 is characterised by a peculiar form of Paludina 



