FAMILY 2. PERISTOMATA. 129 
Pl. CXCVII. Fig. 5. 
PaLtupIna ————— ? Sowerby, Genera of Shells, No. 41. 
Paludestrina —————? D’Orbigny. 
AMPULLARIA, Lamarck. 
Testa globosa, vel globoso-discoidea, epidermide olivacea induta ; spira 
parva, acutiuscula, anfractibus ventricosis, ultimo peramplo, umbi- 
licum szpissimé formante ; apertura integra, plerumque oblonga, 
superné angulatim acuta, margine continuo, labro subincrassato, 
interdum paululim expanso, nunquam reflexo. Operculum annu- 
latum, vel corneum, vel calcareum. 
This genus, which also received its title from Lamarck, was like others 
anticipated by the early naturalists in the sectional subdivision of the 
genera that were in their time recognized. That author is, however, at 
least entitled to the credit of having been the first to arrange the Am- 
pullarize according to their true nature and habits; for whilst Linnzus 
placed them with the Helices, Bruguiére with the Bulimi, and Miller with 
the Nerite, he very judiciously associated them with only such other mol- 
lusks as are inhabitants of fresh water. Lamarck was nevertheless still 
unacquainted with the anatomy of the Ampullariz ; nor were the descrip- 
tions either of De Blainville, or De Férussac, of very elaborate character ; 
now, however, the genus in question has become one of considerable 
interest ; for the labours of Guilding, Quoy and D’Orbigny have disco- 
vered a feature in the organization of these mollusks which had not 
hitherto been noticed, namely, the fact of their having a double system 
of respiration,—both a water-breathing and an air-breathing system. This 
peculiarity of character, first intimated by Guilding in his ‘ Zoology of 
the Caribeean Islands,’ was singularly confirmed by some specimens of 
Ampullariz brought by M. Cailliaud from Africa. The discovery we 
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