The study of the Chitinozoa (possibly an extinct order of marine protozoans) and Tasmanites (probably a family of fossil algae) is generally included in the field of palynology, along with the study of polospores. Work in the Williston basin and other areas containing Paleozoic carbonate rocks indicates that the Chitinozoa and Tasmanites make ideal tools for use by the subsurface geologist. Because of their nearly indestructible nature, these fossils may be concentrated in and recovered from the insoluble residue from drill chips used in normal sample examination. They are well adapted for use as an aid in solving problems of correlation, zonation, and age dating. In the Williston basin the Chitinozoa and Tasmanites have been used as an aid in the reconstruction of the Ordovician surface section in the subdivision of this section, and in extending these subdivisions into the subsurface. These micro-microfossils have aided in the solution of structural problems, and offer possibilities as a tool for age dating of Paleozoic rocks over very wide areas.