Ophryoscolecid Fauna from the Stomach of the White‐tailed Deer (Odocoileus virginianus borealis), and Observations on the Division of Entodinium dubardi Buisson 1923 (Ciliata Entodiniomorpha).

The morphology and division of Entodinium dubardi dubardi Buisson 1923, found by the present writer in the rumen of a white‐tailed deer (Odocoileus virginianus borealis) from the state of New York, are described. E. longi‐nucleatum was found for the first time in this host. A transitional form of E. d. dubardi leading to E. d. cervi Sladecek 1946, was seen. Rotund or orbicular‐like individuals occurring in the material are the postdivisional stages of E. d. dubardi. Comparative study of preparations from the mule‐deer Odocoileus hemionis hemionis, O. hemionus Macrotis, and another white‐tailed deer gave the same results as in the study of the principal host. Very close resemblance of the post‐divisional stages of E. d. dubardi with E. bovis Wertheim and E. orbicularis Bush & Kofoid is noted. New data have been established to regard E. simplex Dogiel as a synonym of E. d. dubardi.