Chainodictyon

Diagnosis. Reticulate colonies, regularly anastomosing. Flattened branches bearing 3 – 12 rows of autozooecia. Vestibule weakly developed. Diaphragms rare. Hemisepta absent. Oval apertures arranged in a diagonal pattern. Autozooecial chambers rhombic in mid-tangential section. Styles absent. Leptozooecia common on the obverse surface of branches. Reverse wall very thin.

Remarks. Chainodictyon Foerste, 1887, differs from Rhombocladia Rogers, 1900, by having a reticulate colony form instead of a ramose one and by the absence of hemisepta. Chainodictyon differs from Kallodictyon Morozova, 1981, in its development of a thin reverse wall and by absence of leptozooecia on the reverse surface of branches. Occurrence. Mississippian of Kazakhstan and Russia, Pennsylvanian of USA, and Russia, and Lower Permian of Russia.

Type species. Chainodictyon laxum Foerste, 1887, by original designation. Pennsylvanian (Upper Carboniferous); USA, Ohio.