David Geyer (1855-1932) is a famous German malacologist. His book entitled Unsere Land- und Süsswasser-Mollusken, and published in 1909, is useful still today, with magnificent plates.
In my copy , the plates are hand labelled with typical old german handwritting.
In addition, a sample of a manuscript written in Kurrent (Deutsche Kurrentschrift), used in Germany until beginning of the 20th century, is stucked on the last page of the book by a precedent owner, maybe Forbes (see the signature) with this comment: “Manuscript Prof. Karschs – geplante Vorarbeit für eine analytische Tabelarisirung”.
We don’t have any information about this Prof. Karsch. We welcome your comments!
Geyer D., 1909. Unsere Land- und Süsswasser-Mollusken. Einführung in die Molluskenfauna Deutschlands. Stuttgart: K. G. Lutz’ Verlag : 155 p., 18 pl.
 Audibert C., private library.