The flora of the Frontier formation
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Material referable to Calamopitys americana, Calamopitys foerstei, Stenomyelon muratum, Kalymma lirata, Kalymma resinosa, and Kalymma auriculata, from the upper portion of the New Albany shale in central Kentucky, is described. All these species are based on the internal structure of stems and petioles. The suggestion is made that the genus Stenomyelon should be included in the family Calamopityeae rather than in a separate family. Relationships of the several species and genera belonging to the Calamopityeae are discussed, and it is recommended that the name Calamopitys be restricted to manoxylic forms (C. saturni Unger, etc.), that Eristophyton be used for the pycnoxylic species which have in the past been placed in Calamopitys, and that Sphenoxylon be adopted for the American species which has been called Calamopitys eupunctata. It is pointed out that the Calamopityeae may be divided, naturally, into two major groups-a manoxylic, protostelic group and a pycnoxylic, medullated group. Stenomyelon is probably in the lineage of the more primitive Calamopityeae, and Endoxylon is presumably the most advanced type now known.
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In the spring of 1910 the writer, working under the direction of T. Wayland Vaughan, geologist in charge of Coastal Plain investigations, undertook a study of the later Tertiary formations of the Gulf Coastal Plain. According to the plans outlined before the work was begun, the beds that had formerly been grouped under the names Lafayette formation and Grand Gulf formation were to be studied with a view to their possible separation into more satisfactory stratigraphic units that might be correlated with other formations which, on the basis of their fossils, had been assigned to their proper positions in the geologic time scale. The original plan included a study of the post-Vicksburgian Tertiary deposits from western Florida to Mississippi River and correlations with formations previously recognized in Florida, southern Alabama, and Louisiana. This plan was subsequently modified to extend the investigation as far west as Sabine River. The field work was interrupted and the office work was delayed by calls for geologic work in other areas, so that the preparation of the reports could not be begun until the spring of 1914.