heterotricha

Century Dictionary and Cyclopedia

1. An order of ciliate infusorians. These animalcules are either free-swimming or attached, naked or loricate, and are entirely ciliated. The cilia form two widely distinct systems, those of the general cuticular surface being short and fine, and those of the oral region of much larger size, cirrose, and constituting a linear or more or less spiral or circular series. The cortical layers are usually highly differentiated, and inclose an even, parallel series of longitudinally disposed muscular fibrillæ. The order contains by far the largest of the infusorians, many of its members being visible to the naked eye, and some ranging in size up to one sixth of an inch. There are 20 or more genera, ranged by Kent in 7 families, Bursariidœ, Spirostomidœ, Stentoridœ, Tintinnidœ, Trichodenopsidœ, Codonellidœ, and Calceolidœ. Heterotricha is one of the four orders established by Stein, the others being Holotricha, Hypotricha, and Peritricha.

GNU Webster's 1913

1. n. (Zoöl.) A division of ciliated Infusoria, having fine cilia all over the body, and a circle of larger ones around the anterior end.