Wahlia pulchella n. sp., a turbellarian flatworm (Neorhabdocoela: Umagillidae) from the intestine of the sea cucumber Stichopus californicus.

Wahlia pulchella n. sp. is described from the intestine of the aspidochirote holothuroid Stichopus californicus. The new species differs from other members of the genus in having the following combination of features: the pharynx lies at the end of the first quarter or third of the body, the intestine extends anterior to the brain, the testes are only slightly lobed, and the penis stylet is straight and less than half the length of the adult worm. Wahlia pulchella has a "secondary uterus" in which there may be up to 12 egg capsules. The validity of the genera of holothuroid-inhabiting umagillids characterized by 2 ovaries and a secondary uterus is discussed. It is suggested that Ozametra Marcus, 1949, be placed in synonymy under Wahlia Westblad, 1930. New diagnoses of Wahlia and Seritia Cannon, 1982, are presented.