VALVATIDJE. 99 



115.) Shell discoid, flat above, and umbilicate 

 beneath ; whorls 3. 

 Valvata cristata. Mutter ', Verm. 198.; Alder, Mag. 



Zool. and Bot. ii. 116. 



Valvata spirorbis. Drap. p. 41. t. 1. f. 32, 33. ; 

 Brard, p. 187. t 6. f. 15, 16. ; Turton, Man. ed. 

 1. 131. f. 115. 



Xerita valvata. Gmel. 3675. 

 Helix cristata. Mont. p. 46. ; Vign. 1. f. 7, 8. 

 Turbo cristatus. Turton, Diet. p. 227. 

 Valvata planorbis. Drap.\. t. 1. f.34, 35.; Tur- 



ton, Man. ed. 1. 132. f. 116. (?) 

 Junior. Valvata minuta. Drap. 42. t, 1. f. 36 38. ; 



Turton, Man. ed. 1. f. 117. 

 In ditches and canals, on aquatic plants. 

 Shell about the tenth of an inch in diameter, pale 

 horn-colour, striate transversely, with three volutions ; 

 the upper surface a little sunk, the under side umbi- 

 licate, so as to expose the interior volutions. 



Mr. Alder observes (Mag. Zool. and Bot. ii. 117.), 

 "Dr.Turton has introduced two other species, V. plan- 

 orbis Drap. (f, 116.), and V. minuta Drap. (f. 117.). 

 into his Manual, but no specimens of them are now to 

 be found in his cabinet." Mr. Alder says he took some 

 pains to investigate these two species when in Paris, 

 on examining three of the principal collections there ; 

 those of the Jardin des Plantes, the Baron de Ferus- 

 sac, and the Duke de Rivoli. " In the latter only. 

 I found any thing under the name of V. planorbis. 

 The specimens (which were originally Lamarck's) 

 were J . cristata Miiller. M. de Ferussac had speci- 

 mens, under the name of V. minuta^ from two differ- 



F2 



