The present monograph is the fourth of six volumes which review the Hypotricha, a major group of the spirotrichs. The book is about the Gonostomatidae, the Kahl

Thorp and Covich's Freshwater Invertebrates, Volume 5: Keys to Neotropical and Antarctic Fauna, Fourth Edition, covers inland water invertebrates of the world.

This is the second book of a series treating the hypotrichs, a major part of the spirotrichous ciliates. It summarises 230 years of morphological, morphogenetic