What you think is alphabetical may not be as alphabetical as you think. For some reason in this Chicago, Illinois, city directory the DeMar entries were split into two alphabetical sections. If I hadn’t “kept looking,” I might have missed the actual entry that I wanted. It’s always a good idea to do a little looking around in printed alphabetical materials for issues of this kind.
Put yourself in the shoes of the person (or people) responsible for indexing and typesetting materials of this before computers.