Description of Epipyxis

Chrysophytes, loricate; solitary, clustered or colonial; usually attached to a substratum or the water-film surface, sometimes free-swimming; lorica composed of overlapping organic scales that are often clearly visible only if stained; lorica tubular, cylindrical, fusiform or vase-like; usually hyaline, sometimes yellowish-brown; lorical scales circular, ovoid or elliptical; composed of interwoven microfibrils; upper margins of scales often bent outwards giving the lorica a denticulate appearance; cell Ochromonas-like, attached to base of lorica by a fine contractile protoplasmic strand containing microtubules; 2 unequal flagella; usually 1 band-shaped chloroplast, sometimes bilobed; in most species with an eyespot at apex, juxtaposed to swelling on base of short flagellum; contractile vacuoles 1-2, anterior, median or posterior; nutrition phototrophic and phagotrophic; reproduction by longitudinal cell division; stomatocysts formed inside or outside the lorica; several species very common in freshwater, often epiphytic on other algae. Taxonomy is based mainly on lorical shape, as well as size, shape and arrangement of lorical scales. Type species: Epipyxis utriculus (Ehrenberg 1832) Ehrenberg, 1838.