Abstract: Cymatium pileare is gonochorism. It s male genital system comststs of testis, vesicula seminalis, vasdeferens prostate gland seminal groove and penis and its female genital system consists of ovary, oviduct , albumin gland, receptaculum seminis, capsule gland bursa copulatrix and vestibule. The sperm delivery ducts in pro state gland, seminal groove and penis are open, and the sperm comprises head and tail with central structure of 09+ 20 axoneme. The penis behnd the right tentacle of the male is the main morphological feature to be dist inguished form the female.