A CONTRIBUTION TO THE INVERTEBRATE FAUNA OF THE OLIGOCENE BEDS OF FLINT RIVER, GEORGIA. By William Healey Dall, Honorary Curator of Mollushs, United States National Museum. INTRODUCTION. The fossils described in this paper were collected on or near the Flint River, Georgia, above and below the town of Bainbridge, by Messrs. T. W. Vaughan, C. Wythe Cooke, and W. C. Mansfield, of the United States Geological Survey. While their state of preservation in many cases leaves much to be desired, the identification of the fauna has some importance for the geology of that part of the coastal plain of the southern United States. A feature of somewhat unusual interest paleontologically is the presence in the upper bed of a rela-tively large number of species of the Cerithiidae, several of them of unusual size, recalling the analogous group in the Parisian Eocene of France, and not paralleled in any of the other Tertiary horizons of the United States so far as known. Attention was called to the presence of these large Cerithia in our southern Tertiary by the writer in 1890,^ but it was not until the present collection was made that material suitable for study was obtained. These fossils are immediately separable into two groups charac-terizing two zones, the upper zone being represented chiefly south of Bainbridge, and the lower zone around and north of that town. The extensive solution which these beds have undergone has probably removed the upper bed in the vicinity of Bainbridge, leaving behind more or less scattered remains of silicified fossils over or near the present surface of the soil. Sixty-one species have been identified from the upper zone, of which 29 are new to science. From the lower zone 39 species were obtained, of which 9 are new. Five of the new species and 14 of the others are common to both zones. Of the forms from the upper zone, omitting the new species, 51 per cent are identical with species found in the Orthaulax pugnax zone at Tampa, Florida, including the two species of Orthaulax. It is probable, allowing for the distance between the two locahties, and for the shallower water indicated by the Flint River species, 'Bull. Soc. Zool. France, vol. 15, 1890, pp. 97-98. PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. 51-NO. 2162. 487
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