Umbonium Shells
Umbonium, often referred to as "button top shells," represents a genus of sea snails, which are marine gastropod mollusks belonging to the family Trochidae, commonly known as top snails.
The shells of species in this genus are characterized by their low-spired, button-like shape. The orbicular shell is depressed, imperforate, and exhibits a polished, porcelain-like surface with a very thin, pearly layer on the inside. The whorls are flattened on top, appearing bright and either smooth or marked with spiral grooves. The small, transverse aperture is broader than it is tall. The outer lip of the shell is thin and sharp, while the inner lip is rounded, terminating in a simple point. Often, the shell's umbilicus is entirely obscured by a thick, smooth callus.
The creature features a pronounced lateral fringe on the foot, sporting three filaments per side. At the tentacles' base on the right, there's a protruding fleshy lobe. The right tentacle itself is unattached, with a compressed eye-peduncle that has a basic eye. In contrast, the left eye-peduncle is cylindrical, equipped with a clear eye and a frontal lobe that is folded and fringed along its edge. Its operculum is hard, circular, and displays a multispiral pattern.
Umboniums can be found throughout the Indo-Pacific region, extending from the Indian Ocean to the Sea of Japan and reaching as far south as the Australian coast.
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Vetigastropoda
Order: Trochida
Superfamily: Trochoidea
Family: Trochidae
Genus: Umbonium
Link, 1807
(REF: Link J. H. F. (1807). Beschr. Nat. Samml. Univ. Rostock 3)(REF: Bouchet, P. (2012). Umbonium Link, 1807. Accessed through: World Register of Marine Species)(REF: Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia)(REF:Proceedings of the Zoological Society of London pt. 21-23 (1853-1855)
Black Umbonium shell
P2-11
One quarter pound of Black Umbonium shells measuring up to 1/2 inch ..... .79
Pearl Umbonium shell
Natural Umbonium shell