62 CLASS GASTEROPODA. 
which the margin of the aperture is reflected. Hel. striata, 
Blainville, Malac. XXXV. iv. 
When this reflected margin is trenchant, they are the AM- 
PULLIN, Blainv. ; and when it is an obtuse ridge, the micas 
GIR, Say. 
There is one species which is remarkable for a border, and 
a stony traverse, on the internal face of its operculaaae 
Hel. neritella, List. 
The organs of respiration in those animals are arranged as 
in the cyclostome, and like the latter they can live out of water. 
MELANTA, Lam. 
A thicker shell; the aperture, higher than it is wide, en- 
larges opposite to the spire; the columella without folds or 
umbilicus; length of the spire very various. 
The melanie inhabit rivers, but are not found in France; 
the animal has long tentacula, the eyes being on their exter- 
nal side, and at about the third of their length. Mélanie 
thiare (Melania amarula, Lam.), Chemn. Tab. 134, f. 1218 
and 1219, from the Isle of France and Madagascar. Add 
Mel. truncata, Lam., &c. 
Rissoa, Fremin. ACMEA, Hartm. 
Differs from melamia, because the two edges of the aperture 
unite above. (Riss. Freminvilii, &c.) 
MELANOPSIS, Féruss. 
Where the form, nearly that of a melania, differs from it ina 
callus on the columella, and in a vestige of an emargination 
near the bottom of the aperture, which seems to indicate a re- 
lation with the terebre of Bruguiéres. (Mel. buccinoidea, 
Féruss.) In the 
