PLATE LXXV. 



Cochlea exigua plana sine limbo. Planorbis. Da Costa. Br. Conck. 

 p. 65. sp. 36. tab. 4. fig. 12. 



A very common species of aquatic snail in stagnant waters and 

 rivers. It is flat and thin, and has not a prominent border as in Helix 

 Limbata of Da Costa, or Helix Planorbis of Pennant, 



