Observations of substrate associated protozoans from depths in excess of two hundred feet in the Great Lakes of the United States are not common. Therefore we welcomed the oppportunity to examine two samples obtained by the research ship "Inland Seas" as part of an exploratory sampling carried out in conjunction with the UMBS. Both samples were collected on August 2, 1969 using a core sampler with a detachable acrylic plastic liner which prevented contamination since the sample was removed with the plastic still around it. ... These exploratory results indicate that a very restricted protozoan fauna exists at depths over 200 feet in Lake Huron; in sample number 1 no species were observed initially and only five were observed initially in sample number 2. This suggests either (1) protozoan species do not reach these areas in quantity or (2) environmental conditions are not favorable for their development. Probably both of these possibilities are operative. However, the development of a greater number of species after the samples stood at room temperature (18 C +-4) indicates that the latter possibility may be important. Since the number of species which appeared on standing differed considerably (1) the precautions taken to avoid contamination appear to have been successful and (2) important qualitative differences probably exist in the bottom sediments. The bottom sediments do not appear to have a unique protozoan fauna but rather a collection of species which might be found in the sediments of a shallow pond.