
I also found this desmid, which I had never seen before.

I referred to Desmids of the United States and couldn't find a definitive match. It could be a Euastrum or a Microsterias.
Considering when Desmids of the united States was written, it seems the microscopes in the 1800's couldn't provide the finest detail. Many of the illustrations get the general shape of the subjects right, but for the most part, the fine details in the drawings are simply stippled in.