medialisella

Medialisella is a genus of small, air-breathing land snails, terrestrial pulmonate gastropod mollusks in the subfamily Helicininae of the family Bithyniidae, the mud snails. This genus is endemic to the Hawaiian Islands.

The shell of these snails is small, thin, and fragile, with a low spire and a wide, flattened shape. The shell color varies from light brown to dark brown, often with a pattern of darker stripes or spots. The shell of Mediaisella typically has 4 to 5 whorls and measures about 5 to 7 mm in diameter.

Medialisella species are found in a variety of habitats, including forests, shrublands, and grasslands. They are often associated with moist, shaded environments, such as the bases of trees or rocks, or in leaf litter. These snails are herbivorous, feeding on algae, lichens, and decaying plant material.

The genus Mediaisella was first described by the American malacologist Henry Augustus Pilsbry in 1910. The name is derived from the Latin word "medialis," meaning "of the middle," and "sella," meaning "seat" or "saddle," referring to the shape of the shell.

There are currently six recognized species in the genus Mediaisella: Mediaisella angustata, Mediaisella concinna, Mediaisella gilvella, Mediaisella hawaiiensis, Mediaisella kahuensis, and Mediaisella subangustata. All of these species are considered to be endemic to the Hawaiian Islands, meaning they are found nowhere else in the world.