Heterotrophic ¯ agellates (Protista) from marine sediments of Botany Bay, Australia Author Lee, Won Je Author Patterson, David J. text Journal of Natural History 2000 34 483 562 journal article 1464-5262 Notosolenus brothernis Lee and Patterson , n. sp. (®gures 9c, 10e±h. Type micrograph: ®gure 10e) Diagnosis . Notosolenus with irregular bulbous outline, 16 Mm long and 9 Mm wide; dorsal face formed by one wedge-shaped and one oblong plate. Description. Colourless, cell outline irregular, about 16 Mm long and 9 Mm wide. The cell is anteriorly pointed and posteriorly rounded. The ventral face is ¯attened. The right half of the cell is slightly thicker than the left. The dorsal face is irregularly raised and seems to consist of two plates. The right plate of the dorsal face is wedgeshaped and shorter, and the left one is rather oblong and extends the full length of the left side of the cell. The wedge-shaped right plate slightly overlaps with the left one and the wide dorsal groove is formed between the two plates. The two ¯agella are unequal in length; the anterior ¯agellum is slightly longer and the front part of the ¯agellum is most active when the cell is moving forwards. The posterior ¯agellum is about 6 Mm long. The ovate reservoir is situated subapically in the right-hand side of the cell and the nucleus is in the mid-position of the left-hand side. Cells move slowly and smoothly. Rarely observed. Remarks. This species has the characteristics of the genus Notosolenus in being rigid, ¯attened and having two emergent ¯agella and no visible mouth. It is similar in length to N. scutulum Larsen and Patterson, 1990 , N. similis Skuja, 1939 , N. triangularis Larsen and Patterson, 1990 and N. urceolatus Larsen and Patterson, 1990 (see Huber-Pestalozzi, 1955 ; Larsen and Patterson, 1990 ), but it can be distinguished from these by its unusual shape. This species is similar to Petalomona s sexlobata Klebs, 1893 in that the dorsal face appears to be separated from the ventral face, but it is distinguished by its recurrent posterior ¯agellum and smaller size; P. sexlobata being 27±30 Mm long (see Klebs, 1893 ).