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On thè genus Pompholyx and its Allies, 
Sub-genus Limncea. Lain. 1801. 
Spire prodnced, sleuder. Last whorl expanded, with a fold 
on thè columella. 
Type Limncea stagnalis. Linn. 
Genus Amphipeplea. Nils. 1822. 
JMantle prodnced over thè outside of thè shell. Shell few 
whorled, dextral. 
T}q)e Amphipeplea glutinosa. Muli, 
Genus Erinna. H. & A. Adams. 1858. 
Animai yet undescribed. Shell o vate-globose, spire short, 
last whorl mnch thè largest, spire obtuse. Columella straight, 
excavated, and with a curved elevated external ridge continued 
in front iuto thè outer lip, which is simple and acute. Shell 
horny, striate longitndinally, dextral. 
Type Erinna Newconibi. H. & A. Ad. 
Genus Strébelia. Grosse and Fischer. 1868. 
Shell involute ; spire short, hardly perceptible ; dextral. 
Animai nnknown. (“ Mnch larger than thè shell,” Berendt.) 
Type Strebelia berendtii ~ Physella berendti. Pfr, 
The fact that some species of Limncea, proper, are dextral 
and some sinistrai, is insufficient cause tor placing thè lattei' 
in a gronp by themselves, unless other characters are present, 
of which at present we have no information. 
Sub-family Planokbin^. H. & A. Ad. 
Faterai jaws present. 
Tentacles filiform. Foot short. Genitalia on thè left side.* 
Genus Planorbis. Guett. 1756. 
Shell dextral, depressed. 
* If we consider thè shells of this group as dextral, they offer thè pecu- 
liarity of having thè genitalia as in most sinistrai shells. Pompholyx pre- 
sents thè same conditions, and is certainly dextral. 
