A view of the entry to the oral apparatus of the green Trichodina that lives on the surface of a freshwater snail collected in central Illinois. In this view the haplokinety and the polykinety of the oral apparatus is cut transversely and an endosymbiotic zoochlorella is evident. The haplokinety is distinguished by a single row of ciliated basal bodies and the adjacent outer polykinety is composed of three rows of ciliated basal bodies. The cortical underpinning of the oral cortex is evident. TEM taken by G. Antipa in 1968 with a Hitachi HU11A operating at 75kV. The negative magnification is 9,500X. The raw film was scanned with an Epson Perfection V750 Pro. This image is best used for quantitative analysis. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 65nm thickness.