MONKOE COUNTY. 975 



cultural purposes may be regarded as the poorest lands in the county. 

 There is also a limited area north-east of Waterloo, where this rock 

 comes to their surface, and where sink holes are abundant, but the strong 

 easterly dip of the strata soon carries it beneath the sandstones of the 

 Chester group, which, with the overlaying limestones and shales, form 

 the bed rock thence to the eastern line of the county. 



About a mile east of Waterloo, the uppermost beds of this group are 

 exposed at their junction with the overlaying sandstone. About ten feet 

 in thickness of the limestone may be seen here, the lower three feet of 

 which is a very hard shell breccia, largely composed of chambered shells 

 belonging to the genera yautilus. Goniatites and Ortlwcerm, and seems 

 tobe the exact equivalent of a similar bed occurring at Greencastle, 

 Indiana, where the rock, though similar in character, is not so hard, and 

 its characteristic fossils may be obtained much more easily, and in a 

 better state of preservation. The beds above this brecciated limestone, 

 contain Lithostrotion proliferum, Zaphrentiss spinulosa, etc., and are imme- 

 diately overlaid by the Chester sandstone. 



One mile east of Columbia, extensive quarries are opened in the lower 

 portion of the upper division of this limestone, both for a supply of 

 building stone, and for lime burning. The rock is evenly bedded, the 

 layers ranging from an inch to two feet in thickness, and abound in the 

 characteristic fossils of this horizon, especially corals and bryozoaus. 

 These quarries show a perpendicular face of about fifteen feet. Quarries 

 have also been opened in the upper portion of this division east of Wa- 

 terloo, but they are mostly in the beds of the small streams, and show 

 but a few feet in thickness of strata. 



Two and a half miles west of Waterloo, on Fountain creek, the upper 

 division of this limestone is well exposed, forming the entire bluffs of the 

 creek for several miles. There is from T.J to 80 feet in thickness of strata 

 exposed here, the lower portion of which is a light-gray, regularly -bed- 

 ded limestone, similar in appearance to the beds quarried one mile east 

 of Columbia. These are overlaid by from 30 to -40 feet of thin-bedded, 

 semi-oolitic limestone, containing a peculiar group of small fossil shells, 

 among which are Straparollus similis, S. planus, DentaUum renustum, 

 Xuculana curta, Toldia? lei-istriata.- Rliynclionella mutata, Terebratula 

 Jiastata, Hemipronites crenistria, (small variety.) and some other undeter- 

 mined species. These beds are overlaid by about fifteen feet of light- 

 gray, or nearly white oolite, in tolerably massive beds, which form the 

 upper portion of the exposure at this locality. The lowest beds seen at 

 this point contain some of the characteristic crinoids of this group, 

 among which are Poteriocrinus Jlissouriensis, Forbesiocrinus tihumard- 

 iatntK. GrapkiocriBtM dactylus, and spines of Archiocidaris Wortheni. 

 These crinoids are associated here with Athyris atnbigua, Spirifer tfeo- 



