Hi Frez, nice to see some of your images! I have never seen such a big Thalassiosira nordenkioeldii, and the detail you show is amazing. Concerning your Coscinodiscus, I think it is C. radiatus, at least that's how I see the extant species in dutch marine waters. Typical characteristic of C radiatus: it's flat as a pancake, no stacking necessary, even with oil immersion. I've got an example at http://www.photomacrography.net/forum/v ... 47276ff31b
Thank you Jacek and Cactusdave. René, I agree with your ID. It is a relatively flat specimen. I changed the name. Sometimes finding an ID only takes a few minutes and other times it takes hours of searching. It's good to get it right though. Thank you very much. The image below is another I have been searching for to ID.