Arion (Carinarion) silvaticus Lohmander, 1937
Arion fasciatus, Arion circumscriptus.
External: Gray dorsum to white on sides; dark, prominent stripes on sides of body and mantle, with lower edge of stripes more distinct than upper; darker in grooves of skin; body is bell-shaped in cross-section; slight keel; white sole; clear mucus (Kerney & Cameron 1979; Wiktor 1983).
Internal: Epiphallus cylindrical and gradually narrowing, sometimes with swelling near atrium; little or no pigmentation of epiphallus; short free oviduct, thinner than epiphallus; short, thick spermatheca duct and ovate/tapering spermatheca; width and length of atrium similar (Kerney & Cameron 1979; Wiktor 1983).
30-40 mm long (Kerney & Cameron 1979).
Native in: Europe (Kerney & Cameron 1979).
Non-native in: USA and S Canada (Chichester & Getz 1969).
Mesic deciduous forests (especially beech), common in mountains and valleys; humid conditions; to 1400 m in Bulgaria (Wiktor 1983; Kappes 2008). Takes shelter in leaf litter and under logs (Wiktor 1996).