columellar

Updated: May 16, 2025

Operculum semicircular, horny, thin, composed of concentric layers with faint traces of a spiral structure at the centro-lateral nucleus, which is on the columellar side; from it there runs a strait rib or process continued nearly to the outer margin, and indicated externally by a depression or groove. A float.

John MacGillivray - Narrative of the Voyage of H.M.S. Rattlesnake, Commanded By the Late Captain Owen Stanley, R.N., F.R.S. Etc. During the Years 1846-1850. : Including Discoveries and Surveys in New Guinea, the Louisiade Archipelago, Etc. to Which Is Added the Account of Mr. E.B. Kennedy's Expedition for the Exploration of the Cape York Peninsula. By John Macgillivray, F.R.G.S. Naturalist to the Expedition. — Volume 2