Arion (Kobeltia) paularensis Wiktor & Parejo, 1989
Arion fagophilus, A. subfuscus.
External: Orange-brown body (Preserved: brown-black body); dark band on each side, with the lower edge of bands blurred and the upper edge distinct; lighter mid-dorsum; bands run along the sides of the mantle and across the pneumostome, with a bit more pigment above the pneumostome than below; blackish head and tentacles; dark thin line or spots usually concentrated in suprapedal groove; cream sole; yellow mucous (Wiktor & Parejo, 1989).
Internal: Black hermaphrodite gland; thick vas deferens; gradually-widening epiphallus; papillae throughout inside of epiphallus; internal papilla where epiphallus joins atrium; no epiphallus retractor muscle; 2-branched genital retractor muscle, attaching to wide part of oviduct and to the point between the spermatheca and spermatheca duct; basal 2/3 of oviduct wide and thick-walled, with two internal folds; oviduct attaches to the side of the atrium, away from the attachment points of the spermatheca and the epiphallus; dark spermatheca with a duct shorter than itself; short atrium with thick walls;
Similar to Arion fagophilus, but A. fagophilus has different colors, light sides, distinct lower edges of side bands, and longer, thicker oviduct (Wiktor & Parejo, 1989). A. subfuscus is larger, more orange with different pigmentation, with thinner oviduct, ephiphallus, and spermatheca that connect close together on the atrium (Wiktor & Parejo, 1989).
Preserved: to 27 mm long, 6 mm wide, mantle 8 mm long (Wiktor & Parejo, 1989).
Central Spain (Sierra de Guadarrama) (Wiktor & Parejo, 1989).
Coniferous forest in mountain valleys; under stones, in hollows in the earth, in moss (Wiktor & Parejo, 1989).
Mature in the fall (Wiktor & Parejo, 1989).