Thus Trautschold gives a number of instances with Ammonites, and Hilgendorf has described a most curious case of ten graduated forms of Planorbis multiformis in the successive beds of a fresh-water formation in Switzerland.

因此，Trautschold 给出了许多与炸药有关的例子，而 Hilgendorf 描述了一个最奇怪的例子， 在瑞士淡水地层的连续床层中有十种分级形式的 Planorbis multiformis。