Green Algae are a very abundant group with more than 7000 species. A few of them are named and pictured below. All in this phylum are marine algae. Red algae are the seaweeds we see up along the shores and beaches. An example is Agar.
Diatoms are photosynthetic unicellular organisims with unique double shells made of silica.
The Dinoflagellates consist of about 2100 different species of unicellular, photosynthetic organisms. Most also have two flagella, and most are also marine. The Brown Algae are some of the largest fastest growing, and most photosynthetically productive eukaryotes. All of the brown algae are marine. An example is Kelp.