Demoulia

Lore & Background

The genus Demoulia was established within the Nassariidae, a family commonly known as Nassa mud snails or dog whelks. Its shells are ovate-globose and covered with a downy epidermis. The spire is short and conical, ending in a papillary apex, and the whorls are depressed. The aperture is ovate, with a thickened inner lip bearing a ridge posteriorly, and the outer lip is contracted, thickened externally, and plicated internally.

Several species have been described, both living and fossil. Among the living species are Demoulia abbreviata, Demoulia nataliae, Demoulia obtusata, Demoulia tryoni, and Demoulia ventricosa. Fossil species include Demoulia conglobata, Demoulia pupa, and Demoulia zbyszewskii. Some names have been brought into synonymy: Demoulia kurodai is a synonym of Nassarius sufflatus, Demoulia pulchra is a synonym of Demoulia obtusata, and Demoulia retusa is a synonym of Demoulia ventricosa.

Reader's Guide

Demoulia represents a distinct lineage within the Nassariidae, contributing to the understanding of mud snail diversity. The genus includes both extant and fossil species, indicating a long evolutionary history. The morphological features—such as the downy epidermis, papillary apex, and plicated outer lip—help distinguish Demoulia from related genera. The synonymies reflect taxonomic revisions that clarify species boundaries. The genus has been included in phylogenetic studies of the Nassariidae, which have revisited the family's systematics. Its fossil record, with species like Demoulia conglobata and Demoulia pupa, provides insight into past marine environments. The genus remains a subject of taxonomic interest, with ongoing refinements to its species list.

Did You Know?

• Demoulia is a genus of sea snails in the family Nassariidae.
• The shell of Demoulia is ovate-globose and covered with a downy epidermis.
• Demoulia includes both living and fossil species.