Deroceras (Deroceras) riedelianum Wiktor, 1983
External: Light coffee body with dark spots on mantle and posterior body; mantle 2/3 body length and with large free/open anterior edge (Wiktor 2000).
Internal: Penis long with a medial constriction; distended apical side of penis likely an appendix; smooth, bent structure on penis apex opposite appendix probably a penial gland; vas deferens attached to the mid side of the penis apex; retractor muscle unbranched, attached at penis apex; cone-shaped stimulator in penis; no rectal caecum (Wiktor 2000).
Similar to D. ponsonbyi, but penis retractor muscle is bifurcate in the latter (Wiktor 2000).
To 23 mm long (Wiktor 2000).
Only Algeria: Skikda and Annaba (Wiktor 2000).
Type Locality: Skikda (Philippeville), Algeria (Wiktor 2000).
In brushwood, cork-oak forest, ruins, and rock piles; resting in moist leaf litter (Wiktor 2000).