3 1 6 Shell Life 



the fresh- water shrimp, or to a caddis-worm ; finally, 

 however, it gets into the frog. Another species is 

 fatal to bats, but works out its destiny in a manner 

 similar to the progress of D. liepatica. First it 

 patronises L. stagnalis or Flanorhis corneus ; its 

 second stage is passed in certain winged insects 

 connected with ponds in early life, and these 

 happen to get snapped up by bats, who thus take 

 at one gulp the bread of life and the seeds of 

 death ! Tennyson's well - known line — " Nature, 

 red in tooth and claw," suggestive though it be, is 

 not adequate to express the fulness of the tragedy. 



The Smooth Pond-snail (L. glabra) has also some 

 resemblance to a small jxdiistris, but though its 

 length is three-fifths of an incli its breadth 

 is only one-fifth ; tlio shell has therefore a 

 more cylindrical appearance, and is thinner 

 and distinctly glossy. The mouth of the 

 slioll is pear-shaped, and at a little distance 

 Avithin strengthened by a broad white rib. 

 There is an umbilical cleft, but it is very 

 minute. The animal is very shy, and seldom 

 ventures from the bottom or sides of its ditch or 

 shallow pool to float along the surface. It is fairly 

 distributed over England, and occurs in a few places 

 in Ireland, Wales, and Scotland, but though plenti- 

 ful where found at all, it is extremely local. 



The two remaining species of Lhnncea are distinct 

 from the others by reason of their short spires and 

 large mouths. The Ear Pond-snail (L. auricidaria) 

 is the larger of these, and its body-whorl is pro- 

 portionately so enormous that the spire seems 

 merely a little ornament added to the top. The 



