594 E. O. ULEICH REVISION OF THE PALEOZOIC SYSTEMS 



the Short Creek oolite member of the Boone as defined by Smith and 

 Siebenthal.'^^ Study of the fossils of these upper Boone beds reveals the 

 fact that while they include a considerable percentage of good Burlington 

 and Keokuk species {Productus magnus, Spirifer rostellatus, 8. neglec- 

 tus, Aviculopecten amplus, and a few others) these are associated with 

 nearly as many more that are elsewhere found only above the Keokuk. 

 In other words, these beds, like the Warsaw at its typical locality, intro- 

 duce a goodly number of Meramecian species, among them Fenestella 

 tenax, Polypora varsoviensis, Spirifer subcardiiformis, S. lateralis-,. 

 Rhipidomella diibia, Eumetria marcyi, and E. verneuilana. On the 

 strength of this evidence, which is in full harmony with diastrophic 

 criteria bearing on the same problem (see page 588), I propose to draw 

 the Waverlyan-Tennessean boundary in southwestern Missouri at the 

 base of the Short Creek oolite and to confine the Boone to the underlying, 

 limestones. Whether the Short Creek oolite and the overlying "Carthage 

 limestone" are strictly correlatable with the Warsaw or whether they 

 are somewhat older can not be decided with the data in hand. 



Locus of faunal evolution and antecedent occurrences. — If we accept 

 the theory that the fossil faunas of the continental basins were evolved 

 'almost entirely in the permanent oceanic basins and only invaded 

 the inland seas when conditions were favorable (see pages 495 to 501), 

 recurrence of faunas is readily explained. While most of the proved 

 recurrences are subsequent to the one which may be said to be typical^ 

 because it has given the name by which each is known, as, for instance,, 

 the Hamilton, the Spergen, the Utica, and the Catheys, it is obvious 

 enough that earlier invasions than the typical one may finally prove no- 

 less common. To a considerable extent these earlier appearances may 

 suggest exceptions to the application of the principle that the introduc- 

 tion of new faunal elements is of high value in stratigraphic taxonomy. 

 But, so far I can see, the danger is more apparent than real. So' 

 long as the occurrences are carefully checked with demonstrated and 

 probable movements of the strandline we are safe from grave miscon- 

 ceptions. Besides, most of the antecedent invasions fall within the same 

 period, and commonly within the same epoch, to which the typical 

 occurrence is assigned. The chief and perhaps only exceptions are 

 among the pelagic faunas, which as a rule were subjected to less strenuous 

 variations in environment than the littorial faunas, and consequently 

 changed more slowly. 



Joplin folio, No. 148, Atlas, U. S. Geol. Survey, 1907, pp. 2-5. 



