Webster’s Revised Unabridged Dictionary · 1913
Capstone
Cap′stone′ (·stōn′), n. (Paleon.) A fossil echinus of the genus Cannulus; — so called from its supposed resemblance to a cap.
Webster’s Revised Unabridged Dictionary · 1913
Cap′stone′ (·stōn′), n. (Paleon.) A fossil echinus of the genus Cannulus; — so called from its supposed resemblance to a cap.