Comprehensive DescriptionRead full entry
DescriptionTheshell is oblique-heliciform, usually thin and opaque. Its surface is smooth and glossy but fine transverse ridges may be present. The embryonic shell is smooth. The 5–7 whorls increase regularly. The shell periphery is usually rounded and the last whorl does not descend below the preceding whorl but is parallel to the preceding suture. The outer wall of the last whorl generally possesses two short longitudinal furrows that correspond with internal apertural lamellae. The umbilicus is narrow and deep. The semi-ovate aperture has an expanded peristome with a reflexed lip. The apertural dentition consists of two parietal lamellae; palatal, basal and columellar lamellae are usually present; upper palatal and supracolumellar lamellae may also be present. Living animals possess a yellowish to reddish reticulated skin. The brown digestive gland and the black kidney are visible through the transparent shell. The upper tentacles are longer than the lower pair with a black eye-spot on the tip of the fully extended tentacle; bright red or yellow retractor muscles show though the transparent skin. The foot is narrow, undivided, the tail short. Genitalia with a long, slender penis; penial sheath short, about half of penis length; internal wall of introverted penis with black to brown penial hooks; vas deferens passes through a short section of penial sheath before connecting distally to penis; vagina and free oviduct short to long, vaginal hooks may be present; gametolytic duct and sac may not extend as far as albumin gland; seminal vesicle present with about the same length from vesicle to talon.