Strata of the Midway Group crop out in a belt from Georgia to Mexico, including well exposed, studied sections in northeast and central Texas. The benthic foraminiferal data assembled by Kellough have been subjected to cluster analysis. Based on these analyses, five different biofacies are recognized in eastern Navarro County. The Littig, Kinkaid, and lower parts of the Wills Point Members represent one shallow-water biofacies. Upper parts of the Mexia clay represent a different community in which some increases in planktonic foraminiferial percentage may indicate deeper stages. The other biofacies are variations of marginal-marine and deltaic-marine environments. These shallow-water communities are similar to the Paleocene Atlantic coastal plain biofacies. Only a few cha acteristic species

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at any particular level dominate the populations. Fluctuations in diversity, high morphologic variability of species, and slow rates of evolution can also be observed. Many qualitative similarities occur between these biofacies and those occurring on and around modern deltas.

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