1895. ] NATURAL SCIENCES OF PHILADELPHIA. 109 



divided into two groups or series, the basal from its greatest develop- 

 ment in Cherokee County was called, tentatively, the " Mount Sel- 

 mau ' ' series, and the upper, from its typical development in Houston 

 County, received the name of the "Cook's Mountain" series. This 

 division was made partly on lithological grounds, the lower or Mount 

 Selman series being generally heavier bedded and made up through- 

 out its greater extent of dark green, and brown sands and sandstones, 

 with very thin seams of iron and while fossiliferous to a greater or 

 less extent the fossils are much fewer than in the upper or Cook's 

 Mountain series, and exist almost altogether in the form of casts. 

 On the other hand the upper series, which includes the highest beds of 

 the Marine stage, is to a great extent loose sands and clays with heavy 

 beds of laminated iron ore and contains a large and beautifully pre- 

 served fauna. 



While probably the distinctive lithological differences between the 

 upper and lower divisions of these beds may not hold good at all 

 points and it may be difficult under the present existing conditions 

 to draw the exact line between them yet the general paucity of life 

 in these lower beds appears in marked contrast with the teeming life 

 of the upper. 



In the northeastern portion of the State, where in Cass, Marion 

 and Morris Counties, these beds appear only as remnants of a wide- 

 spread cover, or as isolated patches forming the low hills of the 

 region, nothing but the lower beds are seen. These are brown, 

 brownish-yellow and green in color, indurated and moderately hard 

 sands and sandstones, and have till now shown no trace whatever 

 of animal life. In Harrison County the greenish- yellow sandstones 

 seen near the Marshall waterworks pumping station' show occasional 

 casts of Venericardia planicosta Lam. , and the same form has also 

 been found near Hynson's Springs, in the same county. These lie 

 at the base of the Marine beds as shown in the section at the pump- 

 ing house. 



1. Brown gravelly sand 5 feet 



o> 2. Laminated iron ore and ferruginous sandstone . 1£ feet 



'£ 3. Greenish-yellow altered glauconitic sandstone 



^ with casts of Veuer icardia planicosta. ... 4 feet 



.2 4. Laminated or thinly stratified red and white 



"a sands and sandy clays forming uppermost bed 



^ of the lignitic in this portion of the county . 45 feet 



