The family of the asterolamprovy includes monocelled diatome with a low-cylindrical armor. Shutters at them round or oval, slightly convex or with a weak radial sinuosity. The center of a shutter unstructured, peripheral part areolirovanny and divided by hyaline sites into wedge-shaped sectors. Includes 2 sorts.
Rod Kostsinodiskus – the main sort of family rich with types and versions (their more than 30, mainly sea, pelagic and neritichesky. Armor low-cylindrical, seldom wedge-shaped. Shutters flat, convex, occasionally concentric - or tangential and wavy. At the edges of shutters often there is a ring of small slit-like outgrowths, and sometimes 1-2 large outgrowths.
Cages usually single, mobile, are more rare sedentary, motionless, are sometimes connected in mobile tape-like or threadlike colonies. Armor longitudinally, cross or diagonalnosimmetrichny. Shutters of a various form: linear, elliptic, round or semi-lunar. Both shutters with the kanalovidny seam located in Kiel or a wing-shaped outgrowth of a shutter. Structure of both shutters identical, presented by the areola, edges and other elements located cross ranks.
Cages single or are connected in threadlike or tsepochkovidny colonies. Armor linzovidny, ellipse, spherical, cylindrical. Shutters in an outline the round. The structure of shutters is presented by an areola and edges, there are trubkovidny outgrowths of various structure.
Cages single or are connected in short chains. Armor low-cylindrical or ellipse. Shutters in an outline round, elliptic, are more rare triangular or polygonal. The structure is presented by an areola, hyaline edges which divide a surface of shutters into radial sectors. On edge of shutters thorns, on poles – outgrowths are quite often developed.
The order includes 1 Achnanthaceae family, the uniting minerals and modern sea and fresh-water types: Achnanthes lancelata (Breb.) Grun., Eucocconeis flexella Kutz., Eunotia arcus Ehr., Rhoicosphaenia curvata (Kutz.) Grun.
Cages at kostsinodiskovy the usually single. Armor low-cylindrical, ellipse or bochonkovidny. Shutters round, flat, convex, concave or concentric - wavy, with various outgrowths. Includes about 10 modern and died-out childbirth.
Family gomfotsimbelovy. At gomfotsimbelovy cages single or form the kustikovidny colonies attached to a substratum by jellylike legs. An armor from a corbel linear, wedge-shaped or elliptic. Shutters linearly-lantsetnye, boatshaped or semi-lunar, slightly asymmetric on a longitudinal or cross axis. Seam usually slightly curved. The family includes 6 childbirth.
Cages of the talassiozirovy are united in colonies by means of the trubkovidny outgrowths which are linked with each other, or jellylike tyazhy, leaving these outgrowths; single cages happen seldom. An armor from a corbel quadrangular, shutters round. At representatives of some childbirth the based disputes are known. The family unites 11 childbirth living mainly in a sea plankton.
The order includes 2 families: Tabellariaceae and Fragilariaceae. Types of Tabellaria flocculosa (Roth) of Kutz are widespread in fresh reservoirs., Tabellaria fenestrata (Lyngb.) Kutz., Fragilatia capucina Desm., Meridion circulare Ag., Opephora martyi Herb., Asterionella formosa Hass., Ceratoneis arcus (Ehr.) Kutz., Synedra lna (Nitzsch.) Ehr.
Cages single or are connected in tsepochkovidny colonies by shchetinka, horns and thorns. The armor cylindrical or prismatic, is more rare the ellipse. Shutters in an outline round, elliptic, three - or polygonal, on poles with outgrowths in the form of horns, hollow thorns or with long shchetinka. Structure from very gentle or large areola. Auksospor, microdisputes and the based disputes are known.
Family of the aktinotsiklovy – the main family of an order containing only one sort. It includes about 10 sea modern and fossil types living in coastal, often desalinated sites of the seas.
Family of the rizosoleniyevy – the central family of an order. In its structure some childbirth. A rizosoleniye sort – the most extensive, it unites mainly planktonic sea types. Cages at them single, are less often connected in short colonies by means of the central thorn. The armor often has an appearance of a long chain, occasionally slightly curved, with numerous inserted rims. Shutters usually in the form of an eccentric cap with the extended top which is coming to an end with a thorn or a long shchetinka are more rare than a shutter slightly convex with shipiky in the center or at edge.