The work of Fichtel & Moll from the year 1798 described numerous important form later used by Montfort in 1808 for the institution of 33 foraminiferal genera. Many of the genera like Nonion, Florilus, Elphidium, Robulus, Tinoporus, Archaias, and Borelis are known to all working with benthic foraminifera. Besides dealing with the taxonomy in detail the present publication re-describes and illustrates the original specimens. The work is accompanied by 30 plates and 33 figures in the text. If further deals with the history of the collection, the origin of the material and the methods of investigation in the late 18th century. An extensive index completes the work. As very few copies of the original work exist the present publication includes a reprint of the 24 hand-coloured copper-engravings of Testacea Microscopica.