Light microscopic observations of infraciliature and morphogenesis in six species of rumen Ostracodinium ciliates

Infraciliature and morphogenesis of six rumen ciliates, Ostracodinium mammo sum, O. munham, O. dilobum, O. rugoloricarum, O. Iwawoi, and O. tiete are d escribed from pyridinated silver carbonate-impregnated specimens. These six Ostracodinium have a similar polybrachykinety arrangement, distinct from t hat of other ophryoscolecid ciliates and intermediate between those of O. g racile and O. damaliscus. Buccal infraciliature is composed of three polybr achykineties, a kinety loop, and paralabial kineties. Small dorso-adoral po lybrachykinety, slender vestibular polybrachykinety. and kinety loop are ch aracteristic. Dorsal infraciliature consists of the dorsal polybrachykinety that extends laterally along the dorsal side of the body. Morphogenesis is different from that of O. gracile, because the right end of ventral primor dium extends dorsally to grow into a right primordium without separation.