Durgella
Durgella is a genus of glass snails in the subfamily Durgellinae of the family Helicarionidae.
Description
The Additional and Principal Characters of the Genus Durgella1. The right and left mantle-lobes moderate, the shell-lobes very ample; the right shell-lobe extends from the anal aperture to the columellar margin, and spreads away over the shell in a broad triangular tongue; the left shell-lobe is reflected slightly over the edge of the shell in front, from near the respiratory orifice, and becomes wider on the lower margin as it approaches the umbilicus, and is also of triangular shape when extended. A large portion of the shell is always exposed.
2. The mucous pore is well developed, with a large overhanging lobe.
3. The jaw is very thin, membranaceous, almost straight on the margin, with a very slight central projection.
4, The odontophore is broader than long, with a central minute, tricuspid tooth; the lateral teeth all similar, minutely 6-cuspid or pectiniform, on a curved edge, very closely set together and exceedingly numerous. 170—1—170+.
5. In generative organs, an amatorial organ present in the Burmese form is absent in the Indian.
6. Shell thin or membranaceous, globose or depressedly conoid; polished, very closely perforate, the columellar margin having no solidity.