Ciliates of the rumen of domestic cattle ( Bos taurus L.)

An examination has been made of the ciliate fauna present in the rumens of four cows on diets of grass hay and fresh red clover ( Trifolium pratense L.). Species of eight genera of oligotrich ciliates and four genera of holotrichs are listed, and the measurements of specimens of each species are summarised. Epidinium Crawley, Entodinium Stein, and Eremoplastron Kofoid and MacLennan were the predominant genera. Buetschlia parva Schuberg, only previously reported on a few occasions, and Charon equi Hsiung were found in all animals. This is the first reported occurrence of the latter organism outside the colon of the horse.