with a revision of thè Limnceidce of Authors. 
341 
Buccal piate ai’CXiate, smooth, dark reddisli brown. Lateral platea 
bkmtly pointed. 
Animai resembling Limncea, with a more slender foot, posteriorly 
ronnded. 
Cusp of centrai tootb trilobed, thè centrai lobe most prominent. 
Base strongly bilobed behind. First three laterals bave thè cusps 
strongly bidentate, thè inner lobe having a notch on thè inner side. 
This side is more strongly notched twice, in thè next three laterals. 
In all, thè cusps are longer than thè base. Seventh and eighth late- 
rals bave foiir denticles on thè cusp, two larger than thè others. The 
ninth and tenth bave five denticles, and thè cusp of thè eleventh is 
prolonged with six denticles. The two remaining pleurals are similar. 
The two inner uncini bave an ovai base, produced anteriorly, and live 
or six denticles on thè rhachidian side. The next is bidentate at thè 
tip and shorter, and thè outermost is quite short and simple. The 
formula is 4.13.1.13.4. There ax-e about sixty rows. 
The ribbon is narrower than in Limncea^ and thè shape of thè 
l'hachidian tooth dilfers slightly. These, with thè characters of thè 
shell, ai’e hardly sufl&cient to constitute it as a distinct genus^ 
Amphipeplea [glutinosa). 
Buccal piate arcuate, smooth. Two lateral accessoiy plates. 
Tentacles triangolar, modei'ately elongate ; eyes sessile on their in- 
ner bases. Genitalia on thè ilght side. 
Mantle mudi produced, neaily enveloping thè shell. F oot bluntly 
roxxnded behind. 
Ova deposited in kidney-shaped or cylindi’ical masses of jelly. 
Teeth. Laterals ; lirst eight, quadrilobate, broad, with cusps veiy 
long in proportion to thè base. The l'emainder with l’homboidal cusps, 
with from two to flve denticles on thè end, and one somewhat poste- 
rior to thè rest, on thè outer side of thè cusp. Central tooth appai-ent- 
ly simple. Foi’mula, 24.1.24. 
Shell few whoi’led, dexti’al, with a short spire, and thè last wlioil 
mudi inflated. 
Planorhis [corneus, lentus). 
Buccal piate arcuate, crenulate. Two narrow, delicate accessory 
plates. 
