Gudeman mentions in his Preface that he had not found or obtained portraits of the following scholars. I have linked to pages where a portrait can be found. If you have or know where these can be found, please contact me.
Scholars for whom "no pictures ever existed":
- Henri Estienne
- Lodewijk Caspar Valckenaer
- Valens Acidalius
- Jacob Bernays
Scholars for whom, if pictures existed, "have so far eluded my long continued search":