154 



Beautiful Shells. 



of Great Britain and Ireland, The mud is prolific 

 of shells; witness the Planorbis family, of which 



79. LimnaBus auricularius (the Wide-eared Mud Shell), 

 Linnceus. 80. L. pereger (the Travelled Mud Shell), 

 Miiller. 81. L. stagnalis (the Lake Mud Shell), Linnceus. 

 82. L. fossarius (the Ditch Mud Shell), Turton. 83. L. 

 glaber (the Eight- Whorled Mud Shell), ibid. 84-85. L. 

 palustris (the Marsh Mud Shell), Linnceus. 86. L. gluti- 

 nosus (the Glutinous Mud Shell), Miiller. 



nine species are here figured. They have been 

 likened to the fossil Ammonites, for which they might 

 be taken as miniature copies. The name is hence 

 a kind of contradiction in terms, compounded of 

 the words which signify " flat " and " ball." The 

 largest is the P. corneus (Figs. 65 and 66), an inch 

 in diameter; the others are P. albus, from one- 



