FORA.MINIFERA FROM THE DEEP WELLS OF FLORIDA

 (WITH -MAP AND THREE PLATES IN TEXT)


 JOSEPH A. CUSHMAN


 A year ago I published the results of a preliminary stu-dy of the foraminifera of a number of deep wells of Florida.* A general account of the geological formations encountered in the drilling was given and but little attention was paid to the distribution of the species themselves. This paper gives the systematic information as to the foraminifera and especially those species of the Miocene and Upper Eocene formations. Those of lower age are not specifically described here as it is a rule of paleontology that new species should not be 'described from well borings because of the uncertainty of depth and the impossibility of giving a type locality from which future collections may be made. As a result these are simply placed in their genera and figures in most cases given in order that they may be available for future comparisons. In the previotLs paper already referred to mention was made of the sources of error which should be kept in mind in the study of well borings. Two things especially may again be noted: first that fossils may fall down from levels above that at which the drilling is' actually taking place, especially when the well is not cased; and secondly, that fossils cannot be encountered until the depth has been reached at which they occur. Therefore fossils appearing below a horizon which has already been definitely fixed must have come from above and are accidental at that level. Many of the foramiiifera from the well bo-ngs are not well preserved and little can be made out except the genus to which they belong. Also in several genera the different species have not been closely studied by workers on the foraminifera. Among numerous genera such as Porystowiella, Nonionina, Ainphistegina, etc., there are many different forms which are apparent in a study of the fossil material of the Coastal Plain and West Indian areas. These are usually

 *Twelfth Annual Report of the Florida State Geological Survey; 1919, PP. 77-103.
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