296 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



leaf impressions are very faint. The latter materials are almost 

 exactly like those in the Columbus Bluffs. In several years field 

 study of the Wilcox, from Alabama to Texas, the writer has never seen 

 Wilcox materials at all like those in the Hickman and Columbus 

 Bluffs, while on the other hand the materials are very similar to those 

 of numerous Pleistocene leaf-bearing river terraces from North Caro- 

 lina to Mississippi. The leaf impressions are the same in all of these 

 sections, those found at each outcrop being recorded in the following 

 annotated list. All but two represent still existing species with cli- 

 matic requirements very similar to those still growing in this same area. 

 A consideration of this list leads inevitably to the conclusion that 

 these outcrops are entirely of Pleistocene age and of fluvial origin. 

 This being true the heavy gravels commonly referred to the Lafayette 

 formation that overlie the leaf-bearing clays are also Pleistocene and 

 not Pliocene and are likewise fluvial in origin as they are also in charac- 

 ter. A transgressing sea forming a blanket deposit shapes pebbles 

 differently in beach shingle. How far eastward from the present 

 river this earlier and Pleistocene alluvial deposit extends it is hard to 

 state definitely, since exposures are infrequent and the problem would 

 require extended field studies. Probably they did not extend very 

 far, since the bluffs northward at Wickliffe, Kentucky, carry plant 

 fossils and are unquestionably of Wilcox age and those between Mem- 

 phis and Randolph, Tennessee, likewise fossiliferous, are of upper 

 Eocene age. There are some well records at Hickman, but they are 

 too indefinite to show the contact with the Wilcox, which, however, 

 is demonstrated to underlie the outcropping Pleistocene. 

 Following is an enumeration of the forms collected : 



Order CONIFERALES. 

 Family PINACEAE. 

 Genus TAXODIUM L. C. Richard. 



TAXODIUM DISTICHUM (Linnaeus) L. C. Richard. 



Taxodiumdistichum (Linnaeus) Richard, Holmes, Journ. Elisha Mitchell Soc. for 

 1884-85, 1885, p. 92— Hollick, Md. Geol. Surv. PH. and Pleistocene, 1906, 

 pp. 218, 237, pi. 68.— Berhy, Torreya, vol. 6, 1906, p. 89; Journ. Geol., vol. 

 15, 1907, p. 339; Amer. Nat., vol. 43, 1909, pp. 432, 433, 434, figs. 1, 2; Tor- 

 reya, vol. 10, 1910, p. 263; Amer. Journ. Sci., ser. 4, vol. 29, 1910, p. 391; 

 Plant World, vol. 14, 1911, pp. 39-45, figs. 1, 2. 



The remains of the bald cypress are very common in American 

 Pleistocene deposits from New Jersey and Maryland southward, 

 where they are represented by the deciduous twigs, conescales, 

 seeds, aments, and stumps with the characteristic "knees." 



A single twig was found associated with the other plant remains 

 in the clays at Hickman, this rarity apparently indicating that the 

 cypress was not abundant in the immediate vicinity or up the river 

 at the time these clays were deposited. 



