Deroceras (Deroceras) altaicum (Simroth, 1886)
Deroceras reticulatum, D. agreste.
External: Mantle 2/3 of body length; light yellow, gray cream, yellow-brown, to black body; dark spots on mantle; dark reticulations on tail, concentrated in skin grooves; narrow spindle-shaped body; pneumostome medial on mantle; light yellow sole; mucus clear, milky when perturbed (Chen & Gao 1989; Wiktor et al. 2000).
Internal: Penis variable in shape, with finger-like gland at apex; vas deferens attached at side of penis apex under gland; penis retractor muscle wide, attached at side of upper penis; long, folded stimulator inside penis; ovate spermatheca narrowing through duct; rectal caecum present (Wiktor 2000; Wiktor et al. 2000).
Similar to D. reticulatum but is smaller and has no groove in penis (Chen & Gao 1989). Similar to D. agreste and unclear whether different species, but D. agreste is larger-bodied with larger penis and different shape of stimulator and gland (Wiktor 2000).
To 30 mm long (Wiktor 2000); preserved: to 24 mm long, 5 mm wide (Chen & Gao 1989).
Mongolia, central China to Yangtse-Jiang River (Wiktor et al. 2000), and former USSR (W Tien-Shan, Dzungar Range, Altai, Sayan, Cisbaikalia and Transbaikalia, Amur Region, Primorye Territory, Kamchatka, Sakhalin, Kuril Ids., Caucasus) (Likharev & Schileyko, MS; Wiktor & Jurkowshi, 2007; in Sysoev & Schileyko 2009). .
To 4200 m altitude; steppe and alpine habitat; moist habitat; under rock, leaf litter (Wiktor et al. 2000).