Homologue

One of two or more features which are assumed to have a common origin. As applied to thecal plates, a homologue is a plate of presumed common origin but with variable shape, position, or relationships to adjacent plates. For example, the small ventral plate in Text-Figure 62C (labelled *1') is presumed to be a homologue of the Kofoid first apical plate in Text-Figure 62A (labelled 1') because of a consideration of plate relationships. Homologues are indicated by a prefixed asterisk in the text: thus, for example, *1' indicates the first apical homologue.