The Centrocestinae are characterized by a fairly large oral sucker that has a double crown of spines. The body is small, and oval to pear shaped. These parasites are transmitted to cats through the ingestion of fresh-water fish. Included here with Centrocestus, the type genus of this subfamily, are also two genera of heterophyid trematodes that others are likely to place in other subfamilies. These two genera, Pygidiopsoides and Pygidiopsis, have characters that are somewhat Centrocestus-like, and for the sake of simplicity, it seemed warranted to use the more general treatment of lumping the three genera together. These latter two genera appear to be transmitted by brackish-water fish.