STUDIES IN THE LIFE HISTORIES OF EUGLENIDA

Abstract

1. In addition to the usually described diagnostic features, Peranema trichophorum shows other and undescribed features as follows: A. The ventral mouth begins as a short straight trough, then widens into a backward curving crescent. B. There is an additional trailing flagellum emerging from the posterior part of the mouth and passing back beneath the body. C. There are two rods of unknown function alongside the reservoir-gullet. D. The blepharoplasts serve as division centers. E. The posterior end of the body is a defecatory area. 2. The possession of the trailing flagellum transfers Peranema from the Astasiidæ to the Heteronemidæ, and justifies the reclassification of Calkins, whereby the family Peranemidæ was dropped.