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Notosolenus mediocanellatus (Stein, 1878) Schroeckh et al 2003 from the northern edge benthos of the spring-fed freshwater coastal pond at Ocean Dunes Apartments in the Atlantic Double Dunes reserve. This sampling site is situated 250 meters from the edge of the Atlantic Ocean and is rich in decaying organic matter. Imaged in Nomarski DIC using Olympus BH2 under SPlan 40x objective plus variable phone cropping on Samsung Galaxy S9+. This cell measures 17 um. Thanks to Jara Kubin for identifying it.

"Gliding euglenid, rigid, cell-outline generally ovate but may be lobed or indented posteriorly, dorso-ventrally flattened, 15–30 µm long and 9–16 µm wide. Two flagella of unequal length: the longer flagellum directed anteriorly during gliding and is about 1.0 CL. The shorter flagellum extends to about one quarter the way down the cell and lies in a ventral groove. The ventral groove connects to the opening of the flagellar canal, and the right margin of the ventral groove projects to form an anterior cusp. There is also a dorsal groove. An ovate nucleus is located in the left hand side of cell. A reservoir with an associated contractile vacuole is situated in the right hand side of cell. The pellicle has very fine longitudinal striations (spaced about 0.5 µm apart). The posterior of the cell contains some food vacuoles. This species is common" (1).

"Remarks: This species was first described as Petalomonas mediocanellata by Stein (1878) from freshwater sites in Europe. The description by Stein is not detailed. His drawings (1878: Tafel XXIII, Figs 12– 14) show three cells with different cell shapes but with a dorsal median longitudinal groove. His drawings and description contain no information about the ventral side of cell nor indicate size. Lemmermann (1913) observed this species from freshwater sites in Europe (Swizerland, Austria and Germany). He gives a size of 22–25 µm and he observed a ventral and a dorsal groove, and a flagellum about the same length as the cell length. They have a second, short flagellum, which is hard to see and which we think Lemmermann may have overlooked. Shawhan & Jahn (1947) also reported the species with one flagellum. Schroeckh, Lee and Patterson transferred this species to Notosolenus because it has two flagella, a character which distinguishes members of Notosolenus from Petalomonas. In shape and size N. mediocanellatus resembles N. canellatus Skuja, 1948, N. lagenos Skuja, 1948 and N. iurassicus Christen, 1962. Notosolenus canellatus is distinguished from N. mediocanellatus because it has a long anterior flagellum (1.5–2.0 CL) and a long recurrent flagellum (about 1.0 CL) relative to cell length and has an anterior collar. Notosolenus lagenos and N. iurassicus differ from N. mediocanellatus because N. lagenos has no grooves and N. iurassicus has one dorsal and two ventral ridges. There is also a resemblance in cell outline and size with P. angusta (Klebs, 1893) Lemmerman, 1913 and N. steini. Petalomonas angusta is distinguished from N. mediocanellatus because it has one groove on the ventral side of the cell and only one flagellum, and N. steini is distinguished by its distinct dorsal ridge. Notosolenus mediocanellatus has a worldwide distribution" (1).

"Notosolenus mediocanellatus (Stein, 1878) Schroeckh, Lee et Patterson, 2003 (Basionym: Petalomonas mediocanellatus) Observations: Rigid gliding euglenid, about 20 µm long, flattened with a highly ovate dorso-ventral profile. One pronounced median dorsal groove and less developed median ventral groove that lead to a wide, subapical, ventral opening to the flagellar pocket. The anterior flagellum, about the same length as the cell, directed anteriorly, and the short posterior flagellum may be difficult to observe. Flagellar pocket and associated contractile vacuole to the right side of the cell. Nucleus is on the left. Numerous small granules, possibly extrusomes, in the anterior portion of the cell. Remarks: Corresponds well with the original description by Stein (1878), except for the presence of the ventral groove in addition to the dorsal groove (Huber-Pestalozzi 1955). The ventral groove has been noted by other workers (e.g. Skuja 1939, Schroeckh et al. 2003). The literature indicates a range of sizes for this species from 7 to 39 µm (Huber-Pestalozzi 1955, Schroeckh et al. 2003). Previously reported widely in freshwater (e.g. North America, Europe, and Australia (Skuja 1939, Huber-Pestalozzi 1955, Schroeckh et al. 2003)" (2).

1. Free-living heterotrophic euglenids from freshwater sites in mainland Australia. Sabrina Schroeckh, Won Je Lee & David J. Patterson. Hydrobiologia 493: 131–166, 2003.
2. Free-living Heterotrophic Flagellates from Freshwater Sites in Tasmania (Australia), a Field Survey Won J. LEE, Alastair G. B. SIMPSON and David J. PATTERSON. Acta Protozool. (2005) 44: 321 - 350

Scale bar= 10µm. Sample taken from Becks Canal plankton tow in Dickinson County Iowa. Valves long with capitate ends apices which are also heteropolar. A tiny apical porefield is present at the end of the one valve. In live samples stellate colonies are held together by mucilage and form star or stellate shaped colonies. Usually a planktonic species.

Phacus gigas, A.M.Cunha 1913; 112 um in length, from the spring-fed freshwater coastal pond at Ocean Dunes Apartements. Sample from northernmost edge benthos situated 250 meters from the edge of the Atlantic Ocean. Imaged in Nomarski DIC on Olympus BH2 using SPlan 40x objective plus phone camera cropping on Samsung Galaxy S9+.

Cells almost round (90–132 × 46–84 µm), flat, posterior visibly asymmetrical; cells terminate with a sharp hyaline tail (on average 20–28 µm long), which is bent sideways. Periplast longitudinally striated. Notice the small lenticular chloroplasts which are accumulated around the center of the cell.