Synopsis Fresh-Water Moi,i,usca 23 



Subclass STREPTONEURA. 



Order PECTINIBRANCHIA. 



Suborder T.^NIOGLOSSA. 



Superfaniily PLATYPODA. 

 Key to the families of Platypoda. 

 { Operculum concentric 2. 



[ Operculum spiral 3- 



f Shell verv large; animal witli both gill and lung Ainpidlaruda. 



[ Shell smaller ; animal with gill only Vivi pander. 



{ Operculum circular, multispiral J^alvatidcc. 



[ Operculum paucispiral 4- 



f Animal with external verge, central tooth with basal denti- 



4. \ cles AmnicoUdic. 



y Animal without verge ; no basal denticles on central tooth 



Plenroccridcc. 

 Family AMPULEARIID.^. 



Shell large, spiral, globosely turbinate; aperture entire; operculum (in 

 the North American species) corneus, concentric, with a sub-central nucleus. 



Animal with snout divided into two long, tentacular lobes ; tentacles long 

 and filiform; eyes on peduncles on the outer bases of the tentacles; mantle 

 with two cervical lobes, that on the left forming a more or less elongated 

 siphon ; genital orifices on the right side in the pallial cavity ; the respiratory 

 chamber divided into two parts, the one being a lung and the other contain- 

 ing a large gill; foot large, simple; jaws two; radula with seven rows of 

 teeth, central large, subtrapezoidal, multicuspid, no basal denticles ; the 

 laterals and marginal narrow, uni- or bicuspid. Oviparous. 



Genus AMPULLARIA Lamarck, 1799. 

 Shell dextral, globose, with a green or brown epidermis; spire short, 

 last whorl rounded, inflated ; umbilicate ; 

 aperture entire, angular above, rounded 

 below, lip simple. y/j \x\ 



iSi^^x^ Tt- ^ 



liiii _^^^^ ^^ 



" iiifliii 



Fig. 70 



Fig. 72 



