Hi Carlos.
Linostoma vorticella is a heterotrich ciliate (in a group with Stentor, Climacostomum, etc). The species used to be placed in
Condylostoma, until revised by Jankowski, 1978.
Sebba's image is clearly a Spirotrich of some sort. I do not know enough to say any more.
The video posted by our friend Michel-Marie is certainly not
Linostoma, but an Oligotrich (probably
Strombidium, or similar).
I'm afraid this is what happens when organisms are casually misidentified and posted to the net. Other people then use them to misidentify their own critters, and things get quite tangled up.

I've done it myself, but I'm trying to mend my ways.
