326 TRANS. OF THE ACAD. OF SCIENCE. 



which is very characteristic of some of the lower limestone 

 beds ; I also observed this coral on Nodaway Eiver, at Ohio 

 Mills, Graham, &c. 



Group C. — This comprises 178', of which 85' or 47 per 

 cent, (nearly \) is limestone, of a gray, buff or ashy-blue 

 color. It is a good material for building and lime. Two 

 traces of coal occur in this Group, and 3' bed of bituminous 

 shale. 



At the upper part we have about 20' of limestone, con- 

 taining Orthis? hemiplicata (Hall). The upper limestone 

 is easily recognized, and being seen at many places I have 

 placed it at the top of this Group ; it caps the hills from 

 near the mouth of Nodaway Eiver as far up as Ohio Mills. 

 It occurs also at Howard's Mill on Platte Eiver, Nodaway 

 County. A two inch bed of " cone in cone," or Tutenmer- 

 gel, occurs at the top of this Group ; it consists of green, 

 fibrous, calcareo-argillaceous matter, and sometimes, as at 

 KunkePs Mill on Nichols Creek, Holt Co., the upper sur- 

 face is weathered and washed out so as to leave exposed 

 numerous beautiful minutely terraced peaks, standing in 

 relief over the surface. 



At the base is 20' of limestone, similar to that at the top 

 of the Group, and having also at top a thin bed of Tuten- 

 mergel. To satisfy the incredulous as to its stratigraphical 

 position, examine the Missouri bluffs 4 miles below Forest 

 City, where the upper limestones are first seen; thence, 

 following down the river bluffs we see them gradually rise 

 higher and higher in the bluffs. At Dallas, the lower lime- 

 stone occurs at the water's edge, and is seen along the 

 bluffs to the Nodaway Eiver ; capping the hills in the rear 

 is seen the upper limestone. The lower bed can easily be 

 traced along the Missouri bluffs, gradually rising as we 

 descend; at Amazonia it occupies the hill tops, and retains 

 this horizon at St. Joseph and throughout Buchanan Coun- 

 ty, gently undulating, and is last seen high in the bluffs 4 

 miles above Weston. This rock is seen on Third Foi-k of 

 Platte Eiver, in the N.W. part of DeKalb County ; near 

 Whitesville, in Andrew County, at bridge on Hundred-and- 

 two Eiver, 4 miles N.E. of Savannah, and caps hills at 

 Jesup's Mill ; on Niagara Creek, near Eochester, it serves 

 as a good guide to the coal, GO feet below ; it is also the 

 highest rock seen on Island branch, in Gentry County. It 

 is sometimes quite cherty. Near Savannah there occurs a 

 dark gray bed at top much valued for building; this bed 

 thins out towards the river, but it is 8' thick at Landers. 

 JPr. Iiogersii abounds in the, lower part near Dallas and at 

 Jesup's Mill, and its interior is often composed of calc 

 spar. 



Group D. — This Group comprises 337', including one 18' 



