Cryptista

The cryptomonads (sometimes called cryptophytes) are a superclass of algae and colorless flagellates, most of which have plastids. They are traditionally considered a division of algae among phycologists, under the name of Cryptophyta. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella. Some may exhibit mixotrophy. They are classified as superclass Cryptomonada, which is divided into two classes:

Cryptista is a phylum of alga-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes.

The kathablepharids or katablepharids () are a group of heterotrophic flagellates closely related to cryptomonads. First described by Heinrich Leonhards Skuja in 1939, kathablepharids were named after the genus Kathablepharis. This genus is corrected to Katablepharis under botanical nomenclature, but the original spelling is maintained under zoological nomenclature. They are single-celled protists with two anteriorly directed flagella, an anterior cytostome for ingesting eukaryotic prey, and a sheath that covers the cell membrane. They have extrusomes known as ejectisomes, as well as tubular m