bicœcidæ

from The Century Dictionary.

• They are ovate or pyriform in shape, with a usually more or less projecting anterior lip-like prominence, are solitary or associated in colonies, and secrete separate horny sheaths or loricæ, which are mostly stalked. They have two terminal fiagella, one long and one short, transparent parenchyma, no distinct oral aperture, and the endoplast and one or more contractile vesicles usually conspicuous. Reproduction results from transverse subdivision and by the separation of the body into a mass of sporular elements. They inhabit both fresh and salt water.