SYNOPSIS. Colpoda elliotti n. sp., found in an enrichment culture from deer droppings, is a small (15–28 by 7.5–17 μ) member of the genus with prominent, rigid, tooth-like processes set between the kineties in the posterior 2/3 of the body. These “teeth” give it a distinctive outline even when viewed at low magnifications. The usual number of kineties is 12; the number of keel notches is 4. Multiplication occurs in reproductive cysts yielding typically 4 tomites. Thick-walled, resting cysts are also formed.

The nuclear apparatus includes a single, crescentic ***micronucleus and a broadly elliptical macronucleus. The latter contains Feulgen-positive material in a few large masses, but no central nucleolus.

The possibility that this species along with other members of the genas is perhaps more closely related to the Hymenostomatida than to the Trichostomatida as now defined is discussed.