Geomalacus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of large air-breathing land slug

Slug

Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...

s, terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pulmonate gastropod mollusks in the family Arionidae

Arionidae

Arionidae, common name the "roundback slugs" or "round back slugs" are a taxonomic family of air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the superfamily Arionoidea.- Distribution :...

, the roundback slugs.

Etymology

The Ancient Greek

Ancient Greek

Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 word geo (γη) means the Earth. The Greek word malacus (μαλαχὀς) means mollusc.

Species

This genus contains the following species:

subgenus Geomalacus

• Geomalacus maculosus Allman, 1843 - Kerry Slug
  Kerry Slug
  The Kerry slug or Kerry spotted slug, scientific name Geomalacus maculosus, is a rare species of medium-sized to large air-breathing land slug...
  
  

subgenus Arrudia Pollonera, 1890

• Geomalacus anguiformis
  Geomalacus anguiformis
  Geomalacus anguiformis is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Arionidae, the round back slugs.- Distribution:This species occurs in south Portugal and central Spain....
  
  (Morelet, 1845)
• Geomalacus malagensis
  Geomalacus malagensis
  Geomalacus malagensis is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Arionidae, the round back slugs.- Distribution :Distribution of Geomalacus malagensis include southern Spain and Gibraltar....
  
  Wiktor & Norris, 1991
• Geomalacus oliveirae
  Geomalacus oliveirae
  Geomalacus oliveirae is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Arionidae, the round back slugs.- Distribution:Distribution of Geomalacus oliveirae include:* Portugal...
  
  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

Reproductive system of gastropods

The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...

 differing from genera Arion, Letourneuxia

Letourneuxia

Letourneuxia is a genus of large air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the family Arionidae, the roundback slugs.-Species:This genus contains the following species:...

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.

See also

• Geomalacus moreleti (Hesse, 1884) is a synonym for Letourneuxia moreleti (P. Hesse 1884)