Geomalacus is a genus of large air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the family Arionidae, the roundback slugs.
Etymology The Ancient Greek word () means the Earth. The Greek word () means mollusc.
Distribution Western Europe
Species This genus contains the following species:Species in genus Geomalacus. AnimalBase, accessed 13 August 2009.Geomalacus. Fauna Europaea, accessed 16 August 2009.
subgenus Geomalacus Geomalacus maculosus Allman, 1843 - Kerry slug
subgenus Arrudia Pollonera, 1890Pollonera C. (1890) Boll. Mus. Zool. Comp. Torino, 5, no. 87, 36. Geomalacus anguiformis (Morelet, 1845) Geomalacus malagensis Wiktor & Norris, 1991 known by some as Geomalacus moreleti (Hesse, 1884) Geomalacus oliveirae Simroth, 1891
Description
Animal limaciform, subcylindrical, blunt behind, with a but little developed mucous pore; mantle anterior, close to the head, concealing a shell-plate; a distinct locomotive disk; respiratory orifice on the right anterior margin of the mantle; genital orifice behind and below the right eye-peduncle. Shell-plate calcareous, ovate, small and solid. Jaw costulated; lingual dentition as in Arion.
The main diagnostic feature of the reproductive system differing from genera Arion, Letourneuxia and Ariunculus is, that species in the genus Geomalacus has atrium with diverticulum. The free oviduct is short; the retractor muscle is attached to the spermatheca duct; vas deferens and epiphalus are long.
References This article incorporates public domain text from reference.Tryon G. W. (1885) Manual of Conchology. Second series: Pulmonata Volume 1. Testacellidae, Oleacinidae, Streptaxidae, Helicoidea, Vitrinidae, Limacidae, Arionidae. 364 pp., 60 plates, page 232, plate 45, figure 14 (radula), figure 15 (jaw).
External links Patrão C., de Sousa J. T., Jordaens K., Backeljau T., Castilho R. & Leitão A. (2013). "Geomalacus and Letourneuxia (Mollusca, Pulmonata): A Cytogenetic Assessment". Malacologia 56(1-2): 333-338. .