SYSTEMATIC INDEX. 



CLASS I. 



MOLLUSCA GASTEROPODA. 



ORDER TRACHELIPODA. 



Family I Neritacea. 



Genus 1. 



Neritina Lamarck. 



I. fluviatilis... p. 1, pi. I, f. 1, 2, 3 



Family II Peristomida. 



Genus 2. 

 Paludin A — Lam arck. 



1. vivipara p. 3, pi. I, f. 4, 5 



2. Achatina p. 4, f. 6, 7 



3. impura 8, 9 



4. ventricosa p. .'5, f. 10, II 



Genus 3. 



AssiMiNiA Leach. 



1. Grayana ... p. 6, pi. I, f. 12, 13 



Genus 4. 

 V ALVATA Miiller. 



1. piscinalis... p. 6, pi. I, f. 14, 15, 

 variety 16, 17 



2. cristata p. 7, f. 18, 19, 20 



Family III Lymntecea. 



Genus 5. 



LymNvEA Lamarck. 



Section I — Elongate; volutions gra- 

 dually enlarging ; spire longer than 

 the aperture. 

 I. stagnalis... p. 28, pi. I, f. 21, 22, 

 23, 24, 2.5 



LyMX.T3A. 



2. palustris p. 9, pi. 11, f. 1, 2 



varieties... 3, 4, 5, 6, 7, 8, 9, 10 



3. minuta pi. I, f. 26, 27 



4. elongata p. 10, pi. Ill, f. 1, 



2, 3, 4 



Section 2 Subovate; body ventri- 



cose ; aperture longer than the spire . 



0. auricularia ... p. 11, pi. II, f. 11, 



12, 13, 14 



6. peregra... 1.5, 16, 17, 18, 19, 20, 



21, 22, 23, 24, 25 



7. involuta p. L3, f. 27 



Genus 6. 

 Amphipeplea Nilsson. 



1. glutinosa... p. 13, pi. Ill, f. 7, 8 



2. lacustris p. 14, f. 5, 6 



Genus 7. 

 Physa Drapernaud. 



1. fontinalis... p. 15, pi. Ill, f. 13, 14 



variety 11, 12 



variety 15, IG 



2. acuta p. 16, f. 9, 10 



3. hypnorum 17, l'^ 



Genus 8. 



Planorbis Miiller. 



Section 1 Volutions devoid of a 



carina, rounded on both sides ; 

 spire slightly concave. 

 1. coi'neus ... p. 17, pi. Ill, f. 21, 



