What is shaped like a snail shell; pertaining to the Helicidæ, or Snail family. Helicoid parabola (Math.), the parabolic spiral called?

helicoid — (Zoöl.) Shaped like a snail shell; pertaining to the Helicidæ, or Snail family. Helicoid parabola (Math.), the parabolic spiral. (Webster's 1913.)

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