82 " Cretaceous. 



Prof. LeoLesquereux*described, fiom the Dakota Group,north of Fori 

 Ellsworth, Nebraska, or its vicinity, Pterophyllum haydeni, Glypto- 

 strobus gracilUmus, Sequoia J'ormosa, Phyllocladus suhintegrifolius, 

 Arundo cretaceus, Liquidam'ber integrifoUum, Populus lancastriensis, 

 PopuUtes eleyans, P. flabellata, P. Salisbury cefotia, P. ovata, now 

 Ampelophyllum ovatum, P. qiiadrangularis, now Hamamelites quad- 

 rangularis, Salix protecefQlia^ Betvla beatriciana, Pag us polycladns, 

 ■Quercus prlmordialis, now Dryo2)hylJtim primordiale, Q. hexagona, Q. 

 ellsivorthanus, Q. ancejys, now Diospyros ancep)s, Q. semialatus, now 

 Anisophyllum semialatum, Picas (?) rhomboideus^ now Phyllites 

 rhomboideus^ Ficus ( f) Jimbriatus, now Eremophyllum fimbriatxim^ 

 Platanus aceroides, var. latior, P. obtusiloba,P. diminutivus,Credneria 

 leco7iteana, now Protophyllum leconteamim, Laurus macrocarpus. 

 Sassafras mudgei, S. subinteqrifoliiim^ Lyriodendroyi giganteicm, L. 

 intermedimn, Magnolia tenuifoUa, Dombeyopsis obtusiloba^ now 

 3Ienispermites obtusilobus, Negundoides acutifolia., Paliurus metn- 

 branaceus, Rhamnus tenax, Phyllites rhoifoUus^ Phyllites amorphus, 

 P. umbonatus^ and Prunus cretaceus. 



In Tennessee,! wherever the Cretaceous rocks are exposed, tliey lie 

 upon Palffiozoic strata. The}' are subdivided into, first. Coffee 

 Sand Group ; secoad, Green Sand Group, or the shell bed; and third; 

 Ripley Group. 



The Cofl'ee Sand Group derives its name from the exposure at Coffee 

 Landing, on the Tennessee river. It outcrops in Hardin and Decatur 

 counties, and overlaps the Western beveled edge of the older rocks, 

 Its outcrop occupies a belt of territory varying from two to eight miles 

 in width, and running more than half wa}^ through the State. It has 

 a n.aximum thickness of about 200 feet. It consists mostly of 

 stratified sands, usually containing scales of mica. Thin leaves of 

 dark clay are often interstratified with the sand, the cla}' leaves occa- 

 sionally predominating. Sometimes b»?ds of dark laminated or slaty 

 clay of considerable thickness, from one to twenty feet or more, are 

 met with in the series. It ver}'^ generally contains woody fragments 

 and leaves, converted more or less into lignite. Silicified trunks of trees 

 are not uncommon. When it passes under Green Sand it becomes the 

 reservoir which yields water when pierced by the well-borers. It is 

 the equivalent of the Tombigbee Sand of Hilgard in Mississipj^i. 



Fossil shells are so abundant in the Green Sand, at some points, 

 that they are gathered by car loads and burned into lime. The maxi- 



'•■■ Am. Jour. Sci. and Arts, 2d ser., vol. 46. 

 t Geo. ofTenn., 1869. 



