FURTHER STUDIES AT VERO, FLORIDA 673 



the fauna of the Aftonian inter-glacial beds of Iowa, yet recognized 

 that "this fauna might have continued on for another stage or two, 

 but by the time of the Illinoian drift it had become essentially 

 modified." 1 It is further to be recognized as not improbable that 

 this fauna may have lingered longer at the south than it did at the 

 north, where the advances and retreats of the ice border were 

 putting the fauna under the stress of an oscillating climate. 



The marine coquina deposit, which lies below all the upland beds 

 and the creek deposits as well, does not bear evidence of great age, 

 its shells being all of living species. This deposit, or perhaps more 

 strictly the beach sands into which it grades upward, are referred 

 by the geologists of this and adjoining states to what has been 

 termed the third or lowest Pleistocene marine terrace formation. 

 The age of this terrace was assigned by Matson to late Pleistocene. 2 



There are good reasons, therefore, in the stratigraphy and the 

 topographical aspects of the deposits at Vero, for regarding the 

 extinct mammals and other vertebrates as continuing to a relatively 

 late date. The aspects of the problem thus developed made a 

 closer scrutiny of the two creek deposits more imperative, for, as 

 we have seen, both of these deposits were late in the history of the 

 formations of the region, and the oldest of these formations bears 

 both a paleontological and a topographical aspect of relative 

 recency. 



This closer scrutiny at the time of the second visit developed 

 evidence both for and against the point previously made by 

 Dr. Sellards that the delicate condition of the fossils — as well as 

 their grouping — -was not consistent with the view that they were 

 derived from an older formation by stream action. Dr. Sellards 

 put forward an increasing number of fossil remains which, on 

 account of their fragile nature, or because of the close association 

 of various bones, he did not believe could have suffered transpor- 

 tation or much disturbance since fossilization. That an occasional 

 specimen of this sort need not be of much significance was pretty 

 effectually established by the finding, among a half-dozen fragile 



1 Symposium, pp. 54-55- 



2 Ibid., p. 40; G. E. Matson, "Geology and Ground Waters of Florida," 

 U.S. Geol. Sum., Water Supply Paper 3ig, 1913, pp. 31-35. 



