Investigations were carried out on the testacea of forest soils in the area of Erlangen and the surroundings of Hersbruck (FRG). A list of species of the different soils is given. Some samples were taken from the national park Bayrischer Wald from harmed pine-forest. Density of colonisation, seasonal variations and the vertical distribution were determined at different sites. For the top layer of organic matter, the humus layer, and the upper mineral soil several types of shells could be characterized. In a deciduous wood, flat, compressed shells settle in the upper layers. Species with robust shells occur in deeper regions. Species of smaller size and those living in the upper soil layers respond faster to the shedding of leaves than bigger ones or those living in the deeper layers. Two new species have been described: Centropyxis matthesi and Trinema clipelina. Placocista lens has been found in the soil for the first time. Various techniques for preparation were used to obtain more shells and to get informations about the structure of the shells. It is possible to dissolve quartz-particles — xenosomes as well as idiosomes — from the shell wall with the help of “HF”. On shells, prepared in this way, inner structures and the construction of the wall can be recognized. The dispersion of elements was determined using “energy dispersive analysis of X-rays” (EDAX). The activity of reproduction of the testacea can be followed up in the natural biotope by marking the shells. Therefore served shells from diatoms which had been accepted as xenosomes by some species of testacea.