Alloioplana stylifera

Alloioplana stylifera (Hyman, 1953) Zygantroplana stylifera Hyman, 1953a: 308–309, figs 53–54 (type locality: Puerto Refugio, Ángel de la Guardia Island, Baja California, Mexico). Alloioplana stylifera – Faubel 1983: 101 (new combination, identification keys). — Brusca 2005: 69 (checklist). Distribution Puerto Refugio, Ángel de la Guardia Island, Baja California; Tiburón Island, Sonora, Mexico. Habitat Benthic. Remarks Alloioplana stylifera was initially described by Hyman (1953a) within the genus Zygantroplana, while Faubel (1983) transferred it to the genus Alloioplana, based on the presence of separate gonopores, a seminal vesicle,an interpolated prostatic vesicle, an armed penis papilla, and Lang’s vesicle. Alloioplana stylifera is characterized by an oblong body with a truncated posterior end, absence of nuchal tentacles, presence of cerebro-tentacular eyes, an elongated pharynx, and separate gonopores located in the terminal region of the body. The seminal vesicle are rudimentary, the penis papilla is armed with a thin and prominent stylet (in proportion of the same size as the vagina), the elongated tubular vagina is oriented towards the posterior-dorsal region of the body.