Observations on The Soil Ciliate Acineria uncinata With Light and Sem Methods (Ciliophora,Pleurostomatida)

The morphology,silverline system and infraciliature of a soil ciliate collected from South Africa,Acineria uncinata Tucolesco,1962 were reinvestigated with light and scanning electron microscopic methods.The results demonstrate that:(1) all three perioral kineties have a structure of monokinetids,of which the PK2 extends only to the anterior 1／3 of the body length,(2) the short dorsal brush consisting of about 10 pairs of basal bodies is not connected with any other somatic ciliary rows,(3) apart from those along the cytostome,the extremely closely set extrusomes are arranged at the most anterior end of the cell and (4) the compressed oral slit are anteriorly "rolled up "and overlapping to the left side forming an oblique spoon-like excavation.The general morphology of this species shows very similar appearances to the original descriptions given by Tucolesco:it has 4-5 kineties (mostly 4!) on the right side (including the 2 perioral kineties),usually 4 (seldom 5) unciliated left kineties (including the dorsal brush and perioral kinety 1) but constant two macronucleus segments which are sometimes very closely connected together.It is still unclear yet whether the short slit-like cytostome is really restricted to the rolled up anterior end (only) as the original author reported,this character could not be confirmed in our observations.