Stratigraphy of the Missouri Palaeozoic. — Broadhead. 81 
Warren, Montgomery, Jefferson, . St. Louis and ('ape Girar- 
deau, and is extensively burned for lime. 
No. 3. Includes about 100 feet of Trenton limestone, em- 
bracing many thin i'ucoidal beds. This is also somewhat cavern- 
ous. In the upper beds are many fossils, including Murchisonia 
gracilis, M.bellicincta, Pleurotomaria lenticularis, Tellinomya, 
Edmondia, Modiolopsis, Endoceras proteiforme, Orthoceras, 
Strophomena, Orthis subwquata, Asaphus, Ceraurus, <■!<■. 
No. 4. Includes about fifty feet of thickly bedded flesh 
colored and drab limestone with many calcspar specks. Black 
river' beds. 
The Upper Silurian is not an important factor in Missouri 
geology. Dr. Shumard reported a considerable thickness in 
Cape Girardeau and St. Genevieve. In Montgomery county 
we find on the streams flowing towards the Missouri about 20 
feet of a coarse gray crinoidal limestone, very cavernous and 
containing but few fossils. At Paynesville, Pike county, 
upper Silurian corals are found and a Tentaculites in gray 
limestone. On Sugar creek, Pike county, are thick bedded 
buff magnesian limestones, resembling the well-known ''Graf- 
ton rock." 
The Devonian is found in Perry, St. Genevieve, Lincoln, 
Pike, Montgomery and Callaway. In the southern and eastern 
parts of Callaway are found numerous corals and well marked 
brachiapods. In Pike county at the base of the Devonian are 
found a few feet of a white oolite which Prof. Swallow has 
referred to the Onondaga, a division of the Corniferous. He 
mentions the occurrence of Acervularia davidsoni (See pp. 
107 and 178 of Swallow's Geological Report, 1855). From 
his description of other rocks containing this fossil I have no 
doubt of its being the fossil that I have identified as Acer- 
vularia davidsoni in the Devonian of Warren and Callaway. 
Prof. Swallow mentions also having found other Devonian 
fossils in the oolite. Near Clarksville are found a few large 
rugose corals which appear to be Corniferous. Overlying the 
oolite at Louisiana are 5 feet of brown shales, and above them 
an- a few feet of black shales. In eastern Missouri this slate 
has only been found in Pike and Ralls. It is supposed to lie 
at the top of the Devonian and to be equivalent to similar 
slates in Arkansas. Tennessee, Kentucky and Ohio. Numerous 
