Genus Cleopatra belonging to Caenogastropda is dioecious. The mature male and female cannot be differentiated externally, but often the removal of shell and differentiation between the two sexes can be achieved by the difference in colour of gonads. The gonads are deep yellow in the male and yellowish-white in the female, the complete reproductive organs of each sex, and commonly formed of the gonad, the gonoduct, and the accessory glands. The male has a well-developed testis found in the spire of the visceral mass, a thin vas deferens and a glandular pallial gonoduct. The latter can be differentiated into a closed prostate gland, a finger-like blind vesicula seminalis, and an opened anterior vas deferens. The sperms are of two types which can be discerned by SEM according to the outline of the head and the length of the flagellum. The female reproductive system is made up of the ovary, having a location corresponding to that of the testis, two main ovarian ductules, the oviduct and the pallial glandular gonoduct. The latter consists of five regions, the receptaculum seminis, albumen gland, capsule gland, uterus and open spermatophore chamber. There is an internal groove in the mantle wall, just anterior to the male or the female slit, to be apparently used for the transfer of the gametes either to the exterior or to the interior.