204 



FRESHWATER FAUNA 



somewhat younger than the Laramie, they cannot be 

 of a very different age. The Cosina beds contain a 

 number of handsome freshwater shells, of which it 

 may suffice to mention Melanopsis and Stomatopsis (Fig. 

 71) ; in the Ajka beds a Unio-like shell Spatha is of 

 interest, since this now lives in the Nile, and its presence 

 has suggested a connection of these beds with Africa, 

 We shall recur to these facts later, and especially to 

 Pyrgulifera and Fascinella, but now r 

 we will resume our exploration of the 

 stratified series. Disregarding many 

 important deposits, we will pass at 

 once to the great development of lakes 

 which characterised the European 

 area in the middle of the Tertiary 

 period. In the Miocene, a great 

 inland sea, the Sarmatian sea covered 

 a large part of Europe and Asia ; 

 commencing west of the present 

 termination of the Alps, it extended 

 past Vienna, covered the south of 

 Russia, the northern part of the site 

 of the Black sea, proceeded still 

 further east, embraced the Caspian 



, ., A , , ., , 



and the sea o Aral, and may possibly 

 h ave b een continued further into Asia. 

 Its waters were salt, and its fauna 

 remarkably poor in species, though such as are present 

 are often represented by an immense number of indi- 

 viduals. At the close of the Miocene the Sarmatian 

 sea was converted into a number of brackish and fresh- 

 water lakes, which persisted throughout the low r er 

 Pliocene or Pontic period, some of them even later; 

 indeed, some of the existing lakes of Europe, notably 

 the Caspian, may be regarded as their direct descenJants. 



from the Cosina 



beds of Istria. 



After stache, from 

 Neumayr, " Erd- 

 gescnicnte. 



