"Animal limaciform, swollen at centre, blunt before, and tapering behind; tentacles simple; shell-plate; no longitudinal furrows above the margin of the foot, and no caudal mucous pit; no distinct locomotive disk; external respiratory and anal orifices on the central right margin of the mantle; orifice of combined genital system on right side of head, halfway between eye-peduncle and mantle ."
मोबाइल