Another Polish rabbi, here shown wearing a fancy "wheel cap" style head covering. On the wiki article is another photograph of him from much later, in which his head is uncovered.
A Kabbalist, he did not wear a kippah. Here we see the trend of "new" branches of Judaism not wearing kippot, a trend that would continue with the early Reform movement.
Oddly, Rav Ganzfried doesn't appear to be wearing any kind of head covering, in spite of being an Orthodox rabbi and the author of the Kitzure Shulchan Aruch.
Rav. Trebitsch wore a tall and large round hat, similar to what was worn in Moscow and also Constantinople. This seems much more typical for Eastern Europe in the late 18th / early 19th Centuries.