. Birds and nature . ur, as well as in brackish and freshwater. They have been found at a heightof over fourteen thousand feet in Thibetand at a depth of eight hundred feet inLake Geneva, Switzerland. Duringtimes of drought when the streams aredried up and the surface of the mud issun-cracked, the species of this familybury themselves deeply in the mud andcover the aperture with an epiphragm, inmuch the same manner as the land fact accounts for the apparent disap-pearance of all life from a pond when itdries up, and its sudden and seeminglyunaccountable reappearance when thepond is
. Birds and nature . ur, as well as in brackish and freshwater. They have been found at a heightof over fourteen thousand feet in Thibetand at a depth of eight hundred feet inLake Geneva, Switzerland. Duringtimes of drought when the streams aredried up and the surface of the mud issun-cracked, the species of this familybury themselves deeply in the mud andcover the aperture with an epiphragm, inmuch the same manner as the land fact accounts for the apparent disap-pearance of all life from a pond when itdries up, and its sudden and seeminglyunaccountable reappearance when thepond is again filled with water. A genus of pond snails closely alliedto Limnaea, but having discoidal orspiral shells, is Planorbis, the flat-orbshells. Instead of dragging their shellsafter them, as in the last genus, they carrythem perfectly perpendicular, or perhapstilted a little to one side. The animalsare very rapid in movement, more so thanLimnaea, which arc rather delight in gliding rapidly about, 128.
Size: 1178px × 2121px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, books, booksubjectnaturalhistory
