The shell of the Planorbis is thin, light and disk-like in form. The can creep along solid bodies, or swim upside-down through the water.
Hazlitt Alva Cuppy PH.D., Editor Beauties and Wonders of Land and Sea (Springfield, OH: Mast, Crowell & Kirkpatrick, 1895)
2400×2008, 1.3 MiB
1024×856, 196.0 KiB
640×535, 97.4 KiB
320×267, 36.0 KiB