Trachelomonas
Trachelomonas is quite common in freshwater environments, and sometimes forms brownish blooms. Like the other euglenoids, this genus can be found in both hard and soft water habitats of varied pH and light levels - mainly marshes, swamps, bogs, mires, and other wetlands with an abundance of decaying organic matter, as well as other varied habitats.   Researchers have found fossils of cells that are closely related to Trachelomonas from nearly 60 million years ago.