from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of the freshwater air-breathing mollusks belonging to Planorbis and allied genera, having shells of a discoidal form.
from the GNU version of the Collaborative International Dictionary of English
- n. Any fresh-water air-breathing mollusk belonging to Planorbis and other allied genera, having shells of a discoidal form.
from The Century Dictionary and Cyclopedia
- n. The typical genus of Planorbinæ.
But P. planorbis is characterized by a keel around the periphery of the shell, which the specimens from Karagöl are lacking.
Lacking a microscope, we initially thought they were Planorbis planorbis, a species recorded from Turkey before.
Of the many varieties, one, the largest, the horn-coloured _planorbis_, emits a purple dye.