The increasing acceptance of the concept of a species varying in time, comparable to the geographic variation of species, alters the entire nomenclatural basis of biostratigraphy. Biostratigraphers must reorient their basic concepts to those of correlating samples from supplies that represent some unknown segments of the biological continuum. Biostratigraphers cannot continue to use taxa (species of the "New Paleontology" for smaller biostratigraphical units because they are not sufficiently refined to meet the need for detail in modern and future stratigraphy.