Tailess Vorticella or Epistylis?

[Plasmid]

Found this bell shaped ciliate swimming around, but can't verify if it is a Vorticella.
The second video is that of a Diatom, there is a string like structure that can be seen inside it, similar to that of multinucleated ciliates and so was wondering of anyone had a clue as what it could be.
Thank you

[Bruce Taylor]

The peritrich ciliate in the first video has come loose from its stalk, so it can't be identified below order, Sessilida. Yes, it could be Vorticella...or Pseudovorticella, Carchesium, Haplocaulus, Epicarchesium, etc. A clear view of the stalk can usually get the ID down to family. However, getting to genus can require more detail than that (for instance, to distinguish Vorticella from Pseudovorticella we often need to see a pattern called the "silverline system", which can be very difficult to detect without special stains).

[Plasmid]

Thank you Bruce.