species although some of these may be less familiar to 

 the average worker than other species previously there 

 referred. 



The present volume of studies in Forammifera is 

 divided into two sections: the first concerned with 

 planktonic species, and the second with benthonic 

 species. During the past decade the value of plank- 

 tonic Foraminifera for purposes of interregional corre- 

 lations and for detailed stratigraphic zonation has 

 won increasing recognition. Their value is especially 

 pronounced in zonation problems in beds nearly or 

 completely devoid of macrofossils. Here, the plank- 

 tonic Foraminifera have proved indispensable to a 

 clear imderstanding of the stratigraphy. In the 

 Tertiary strata, members of the planktonic families 

 Orbulinidae, Hantkeninidae, Globorotaliidae, and cer- 

 tain of the Heterohelicidae are as useful for zonations 

 as the ammonites were for the Mesozoic. In reality 

 they are the "ammonites" of the Tertiary, having short 

 stratigraphic ranges and wide geographic distribution. 



In the Caribbean and in many areas of South America 

 workable zonations in use by oil companies are almost 

 entirely based on planktonic Foraminifera. American 

 writers have tended to neglect the planktonic Foraminif- 

 era in stratigraphic and commercial micropaleontology, 

 in part because of the chaotic condition of the literatiure 

 and in part because benthonic species also work well in 

 their areas of operation. However, as offshore drilling 

 progresses and as thick sections of offshore beds are 

 encountered, the planktonic Foraminifera will prove 

 to be an added and welcome tool for correlation. 



Many of my colleagues have decried the fact that 

 planktonics are difficult to use because there is too much 

 variation in the species themselves for clear delineation. 



Although this difficulty has been aggravated by the low 

 caliber of illustrations in the literature, from which it is 

 often impossible to identify the species, a detailed 

 study of the planktonics based on actual specimens and 

 good illustrations will show them to be no more variable 

 or difficult to work with than the human species. 



Part I has as its first objective the development of a 

 logical classification of the families and genera of the 

 planktonic Foraminifera. Its second objective is to 

 describe various planktonic faunules, presenting ade- 

 quate illustrations and clear descriptions with the hope 

 of progressing toward a better understanding of inter- 

 regional correlations and perhaps eventually to develop 

 a uniform world-wide zonation. Its third objective is 

 to present the results of studies that may be of use to the 

 economic paleontologist in local weU-to-weU correla- 

 tions or in exploration in unknown areas. The first 

 two aims lead inevitably to the third, for science is 

 valuable to man only insofar as it is his servant, and our 

 artificial taxonomy, which is only man-made and not 

 a product of nature itself, must be made useful if it is to 

 be worthwhile. 



Part II of the volimie is concerned with the revision 

 of some existing genera, and the description of certain 

 new genera and species of benthonic Foraminifera; some 

 of the papers being concerned with a taxonomic group, 

 others with an ecologic or a stratigraphic assemblage. 

 They are thus more varied in character than the papers 

 included in the planktonic section, but it is hoped that 

 all will contribute to a better understanding of one or 

 more of the many aspects of our knowledge of the 

 Foraminifera. 



Alfred R. Loeblich, Jr. 



