This file addresses a long-standing issue in the study of fossil stromatoporoids, that is the validity of their taxonomy. It uses a case study of three well-established genera of stromatoporoids from the Silurian strata of England, but these genera show overlap in their skeletal architecture, that casts doubt on their validity as genera. The document describes these fossils in detail and compares them, in order to try to arrive at a workable solution to understand their taxonomic status. This study is potentially of great importance to develop further understanding of these fossils and their applications in analysis of the limestones in which they occur