CONCHOtOGY. 



105 



*P. Nuttaliana. 

 *P. virens. 

 *P. pallida. 

 *P. subcarinata. 



*P. unicolor. 

 *P. nuclea. 

 *P. decisa. 

 *P. fuscus. 

 ■P. Nickliniana. 



3. Genus AmpuUaria. PI. X. 



Animal. Inflated, globular, spiral ; foot oval, with a trans- 

 verse furrow at its anterior edge; head wide; tentacula superior, 

 very long, conical and pointed ; eyes situated at their external 

 base, and supported upon a very apparent peduncle ; mouth ver- 

 tical, situated between two lips disposed in form of a horse shoe 

 and forming a kind of muzzle; no superior tooth; a bristly lingual 

 band, but not prolonged into the abdominal cavity ; a very large 

 respiratory cavity, divided in two by an incomplete horizontal 

 partition. 



Animals of this genus are oviparous; producing an q^,^ nearly 

 as large as that of a pigeon, in which is found the young animal 

 complete, and in a perfectly formed shell. 



Shell. This genus appears to partake of the characteristics, 

 both of the Paludina and the Natica, being fluviatile and fre- 

 quently attaining a large size ; spire very short, the last whorl 

 much larger than all the others together ; globular, very ventri- 

 cose, umbilicus small, forming a compressed funnel shaped aper- 

 ture, without interior callosity ; aperture longer than broad with 

 margins united ; columellar lip thickened, projecting and reflected 

 over the umbilicus; operculum horny. Inhabits the rivers of 

 Europe. Thirteen species. 



AmpuUaria vivipara, 



A. fasciata. 



A. effusa. 



A. virens. 



A. avellana. 



A. fragilis. 



AmpuUaria rugosa. 

 A. canaliculata. 

 A. Guinica. 

 A. carinata. 

 A. intorta. 

 A. conica. 



'A, Pealiana^ 



