Tethya is a genus of sea sponges belonging to the family Tethyidae. Members of this genus all have a spherical body form and some are known to be able to move at speeds of between 1 and 4 mm per day.

Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck, often known simply as Lamarck, was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolog