GASTEROrODA 



301 



Z. peregra feeds on the green fresh-water algae ; L. sfagnalis 

 prefers animal substances. 



Fig. 128. L. stagnalis. 



Distribution, 90 species. Europe, Madeira, India, China, 

 North America. 



Fossil, 70 species. Wealden — . Britain, France. 



Sub-genus. AmpliipepUa, Nilsson. A glutinosa, PL XII., 

 Fig. 31. 



Shell globular, hyaline. 



Animal with a lobed mantle, capable of expansion over the 

 shell, 5 species. Europe ; PhilijDpines 



Fig. 129. Cpulchra. 



ChilI^^ia, Gray. Chilian-snail. 



Example, C. pulchra, D'Orbigny, Eig. 129 



Synonym, Dombeya, D'Orbigny. 



Shell oval, thin, ornamented with dark spots or wavy bands ; 

 columella thickened, with one or two strong prominent folds. 



Distribution, 18 species. South America ; in clear running 

 streams. 



Fossil, 1 species. Miocene, Eio Negro, Patagonia. (D'Orb.) 



Physa, Draparnaud. 



Type, P. fontinalis, PI. XII., Fig. 32. 



Etymology, Physa, a pouch. 



Synonyms, Bulin, Adans. Eivicola, Fitz. Isidora, Ehr. 



