A Field Guide to the Snails of Lord Howe Island

104 Microcystidae (Tiny glass-snails) Genus Melloconcha Iredale, 1944 Shell. Size: H = 1.8-4.5 mm, D = 3.7-8.8 mm. Colour: Pale golden to dark amber brown. Shape: Discoidal, trochoidal or domed with a low to elevated spire; whorls rounded or flattened above and rounded below an angulate periphery; sutures weakly impressed to strongly channelled. Sculpture: Shell smooth and glossy with fine, incised spiral grooves. Aperture: Ovately lunate; width greater than height; columella sometimes with a tooth. Umbilicus: Closed. Animal. Body cream to black, with grey neck and eyestalks. Right shell lappet present; left shell lappet reduced or absent. Habitat and occurrence. Endemic to Lord Howe Island, where it is widespread. Semi-arboreal, living primarily in live palms but also in leaf litter. Remarks. Melloconcha can be distinguished from closely related genus Innesoconcha by its generally smaller size and by the reduction or absence of the left shell lappet. The individual species can be distinguished by a combination of shell shape and size and shell/body colour, as well as anatomical differences. Palms are the most common habitat for microcystids. Image I. Burghardt.