plagiostomidæ

from The Century Dictionary.

• A family of small, usually cylindrical turbellarians of the order Alloiocœla, with one genital opening, no accessory female apparatus, and with the testicular follicles in front of, alongside, and behind the brain. The pharynx varies in position and size, and there is no otocyst. It includes several genera, among which are Plagiostomum, Acmostomum, and Vorticeros.