| 释义 |
pla·nor·bis
\-bə̇s\ noun
Usage: capitalized
Etymology: New Latin, from Latin planus flat + orbis ring, disk, orb — more at floor
: a widely distributed genus (the type of the family Planorbidae) of snails with secondarily acquired gills, a fundamentally sinistral body, and a more or less discoidal and planospiral shell that may be either dextral or sinistral |