Abstract
In the survey conducted on 10 zebu cattle, Bos indicus L., 1758, in Thailand to make clear the geographical distribution of rumen ciliates, one new genus and one new species belonging to Buetschliidae, one new species of Diplodinium, and one new forma of Entodinium parvum were recognized. They were described as Parabundleia ruminantium gen. n., sp. n., Diplodinium mahidoli sp. n., and Entodinium parvum forma monospinosum forma n., respectively. P. ruminantium is elliptical in shape and 37-50 μm in length, and has two anterior and one posterior ciliary zones. The two anterior ciliary zones are situated around the cytostome and near the concretion vacuole, and the posterior one occupies very narrow area besides the cytoproct. D. mahidoli is one of the largest diplodinia, 117.5-167.5 μm long, and has broad ectoplasm and two caudal processes. Of these processes, the right one forms a spine but the left one a lobe or a spine. So that this species was classified into two formae on the basis of the shape of the left caudal process, namely, D. mahidoli forma mahidoli with a lobe and D. mahidoli forma bispinosum with a spine. E. parvum forma monospinosum is elongated-ellipsoidal in shape with one spine at the left posterior extremity of body. The body is 35-45 μm long. The morphological characters of this ciliate were the same as those of E. parvum Buisson, 1923, except the possession of a caudal spine, so that this ciliate was assigned in this paper to one forma of the species.
