11 



Sect. 2. Edriophthalma. 



Eyes sessile, or on very short tubercles on the outer side of the 

 base of the tentacula. Male organ on right side of nape. ^.r^.il.^X*^'^^ '^ 



A. Shell free, spiral. Operculum annular. Teeth few, unequal, -'Ziii^fei^^ 

 1 central and 3 lateral on each side, converging. Male or- 

 gan at base of right tentacle. Lister, Cvivier. Gills three 

 ranges of filaments. 'Fluviatile. 



Fam. 11. ViviparidcB. 



1. ViviPARUS, n. 251=Viviparella, Rafin. Opercuhim horny, ■U\^-^^ / 



nucleus near the middle of inner side. f 



1 . V. vulgaris. Helix viviparus, Muller, 1. 124. f. 3 ? ; Cuvier, t.l24. 



f. 6. Nerita viviparus, Sturm, 1. 124. f. 9. AjJ^ 



2. V. bengalensis, Hardwicke, t. 124. f. 2. India. /} / V^-'fiJ' 



3. V. ampullariformis. Paludina a., Eydoux, 1. 127 a. f. 5. iJ^' Y^ 



4. V. decisa, Haldm. t. 310. f. 10. 



2. Paludomus, n. 2&2=Taplifa, n. 219, is only a subdivision. 



Opercidum horny, nuclcusiiear the front of outer side. 



•«-i. P. conicus. Gray, P. Z. S. 1849. 



2. P. ? Paludine boueuse, Eydoux, t. 127 a. f. 4, edge of mantle 

 festooned. 



3. BiTHiNiA, n. 253. Operculum with a shelly internal coat, 



nucleus subcentral. 

 1 B. tentaculata. Cyclostoma impura, Sturm, 1. 124. f . 8 ; Chiaje, 

 t. .f. . 

 B. viridis. Cyclostoma v., Sturm, t. 124. f. 7- 



4. Nematura, n. 207. Operculum ftnmulftr , ovate, thick, shelly; 3/ > • '♦^ 

 nucleus subcentral ; shell mouth contracted. 1 . N. Deltae. 

 2. N. polita. ^JC^'-^y ^ 



C 



B. Shell spiral, free. Gill inclosed, in one or three lines on left 

 side of mantle-cavity. Operculum spiral. Teeth few, cen- 

 tral 1, lateral 3'S, converging. 



Fam. 12. Littorinidce. > 



Foot moderate, for walking ; trunk produced, wrinkled, not re- t 



tractile ; tentacula far apart on side of head ; gills 2, one very 

 laro-e, occupying nearly the whole surface of the cavity and formed 

 of flat free plates. Amphibious. 



a. Operculum ovate, few whorls. V-t-v-t^^ •■. -i 



1. AssiMiNEA. n, 193. Eyes on pedicels, united to the short (-<^ "^^^^ZZX 



tentacles. a^i^x^ ^^-^ttld-^ 



1. A. Grayi, Berleley, 1. 123. f. 6 ; Gray, t. 51. f. 8. ^^ i± £LjL~ 



2. LiTTORiNA, n. 194. Eyes sessile. ^y-^v^ C U I 



1. L. littorea. Turbo 1., Cuvier, t. 51. f. 4. 



2. L. varia. Lit. varie'e, Eydoux, t. 127 «• f- 2. 



