hypotricha

Century Dictionary and Cyclopedia

1. An order of ciliate infusorians. These animalcules are free-swimming, and are mostly flattened or compressed; the locomotive cilia are confined to the inferior or ventral surface, and often variously modified; the superior or dorsal surface is usually smooth or glabrous, but occasionally bears a few scattered or longitudinal rows of immotile setose cilia; the oral and anal apertures are conspicuously developed, and ventrally located; and trichocysts are rarely developed. The order was founded by Stein, and is contrasted with Heterotricha, Holotricha, and Peritricha. It contains about 6 families and 40 genera.

GNU Webster's 1913

1. n. (Zoöl.) A division of ciliated Infusoria in which the cilia cover only the under side of the body.