Ariunculus
| Ariunculus | |
|---|---|
 |
|
| A live individual of Ariunculus speziae, coin diameter is 16.25 mm | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): |
clade Heterobranchia clade Euthyneura |
| Superfamily: | Arionoidea |
| Family: | Arionidae |
| Genus: |
Ariunculus Lessona, 1881 |
| Diversity | |
| 2 species, each in its own subgenus | |
clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
informal group Sigmurethra
Ariunculus is a genus of air-breathing land slugs in the family Arionidae, the roundback slugs. Sometimes it has been considered as a subgenus of Arion, and sometimes the subgenus Ichnusarion has been raised to generic rank.
The stem of Arion plus the suffix -unculus, which is a diminutive in Latin. Hence "little Arion". Pollonera justifies why "Ariunculus" is appropriate rather than "Arionculus" (cf. "homo" and "homunculus").
The subgenus name Ichnusarion is also based on "Arion", to which has been added "Ichnusa", a Latin name of Sardinia, where the single species of this subgenus is endemic.
Only two species are currently recognised:
subgenus Ariuncululus
subgenus Ichnusarion Pollonera, 1890
Other species have been discounted as distinct members of the genus:
Genital characters that have been proposed as diagnostic of the genus are:
At least in one species of Ariunculus, this last character reflects that sperm is transferred naked rather than in a spermatophore formed in the epiphallus; this is a fundamental contrast with Arion and Geomalacus.
Ariunculus differs from Geomalacus, and is similar to Arion, in that the caudal gland is prominent and the mantle contains only calcareous granules rather than a shell plate.
...
Wikipedia