Usilla avenacea
NameUsilla avenacea
Scientific NameUsilla avenacea
Common NameNo widely accepted common name
FamilyPisaniidae
GenusUsilla
Speciesavenacea
Geographic DistributionIndo-Pacific, particularly known from Western Australia.
Habitatintertidal
Shell Shapefusiform
Average Size (mm)10-15
Identifying FeaturesStrong cancellate sculpture formed by intersecting spiral cords and axial ribs, often nodulose. Prominent, numerous white denticles on the inner side of the outer lip. Short siphonal canal. Dark aperture interior with a contrasting white denticle band.
Raritycommon
Author Citation(Sowerby, 1834)
Description
Usilla avenacea is a small, robust marine gastropod shell characterized by its fusiform shape and intricate sculpture. The shell exhibits prominent spiral cords and axial ribs, often forming nodules at their intersections, giving it a textured, cancellate appearance. Its coloration typically ranges from dark brown to reddish-brown, frequently adorned with lighter, often whitish or greyish, spiral bands or blotches, and darker axial markings, creating a mottled or checkered pattern. A distinctive feature is the aperture, which is dark internally, but the inner side of the outer lip bears a series of prominent, white denticles (teeth). The siphonal canal is short and slightly recurved. This species is commonly found in its habitat.
