Colonial rugose corals are rare and generally poorly diversified in the Upper Pennsylvanian of the western interior region, conterminous USA. Paraheritschioides n.gen., which includes P. grandis n.sp., and P. complexa n.sp. from the Oquirrh Formation in Idaho, provides a new tool for distinguishing Upper Pennsylvanian rocks in the western interior. The new genus is also represented by P. stevensi (Wilson) in the Permian McCloud Limestone of northern California. The new family Heritschioididae is created to include Paraheritschioides, Heritschioides, Amandophyllum and Heintzella.-Author