“…Also, H. opaca resembles Abollifer prolabens Downloaded by [University of Alberta] at 21:26 01 December 2014 Vù rs, 1992; A. prolabens has one¯agellum, but sometimes the second shorter agellum may appear before cell division ( Vù rs, 1992a) . Heterochromona s opaca resembles Cruzella marina (see de Faria et al, 1922), but can be distinguished because C. marina is¯exible and has a long anterior¯agellum. It is distinguished from other species of Heterochromonas by the anterior protrusion.…”