VERMILION COUNTY. 255 



thickened up to from twenty inches to two feet. The overlying shales, through 

 all the outcrop, are generally quite full of the conical, bony teeth, or dermal 

 scales of Petrodus occidentalis, constantly accompanied by the long, slightly 

 curved, and fringed fin-spine, and the small rhomboidal scales which there is 

 every reason for referring to the same species. The accompanying black fer- 

 ruginous limestone commonly contains more or less of the same fish remains, 

 accompanied by CardiomorpJia Missouriensis. 



The beds of the lower part of the section show no outcrop within this county, 

 but as they will very probably be met with in any moderately deep borings 

 which may be made near the State line, east and northeast of Danville, it was 

 thought best to complete the section as far as possible ; and some general state- 

 ments regarding these lower beds may not be out of place here. 



No. 43 is a valuable bed of low grade ironstone. No. 44 generally contains 

 a heavy band of tolerably compact sandstone, such as forms the Hanging Rock 

 on the Big Vermilion, a few miles below the State line. No. 46 commonly 

 presents two or three, and sometimes four or five partings of coal, separated by 

 shale and fire clay, some of which are occasionally thick enough to work profit- 

 ably. No. 49 is too thin a seam to command attention, until nearly the entire 

 supply of the tolerably thick seam in the neighborhood has been used up. It 

 outcrops along the Big Vermilion below Eugene. No. 53 is a thick scam of 

 semi-block coal, tolerably well fitted for smelting iron in the raw state. Two 

 or three seams of coal occur below this, at Thome's ferry, just below the mouth 

 of the Big Vermilion; but, as their extent and regularity are unknown, and 

 they are not represented at the point where the bore of the salt well was put 

 down, it was thought best to omit them from the general section. They prob- 

 ably represent partings of coal No. 1. Below all these coals, but not repre- 

 sented in the section, from lack of certain connections, is the heavy bed of lime- 

 stone, with underlying shales, at Perrysville, Ind. These beds are full of fos- 

 sils, and it is interesting to note that among them are some of very wide dis- 

 tribution, such as Athyris subtilita, Petrodus occidentalis, and Aviculopccten rec- 

 talatcrarea, the latter of which was formerly considered especially character- 

 istic of one seam, but which presents itself to the explorer in every one of the 

 black shales of the general section, from this basal bed to No. 4 of the section. 



Economical Geology, 



Coal. After the fertile prairie soil, which has been already spoken of, this 

 mineral naturally occupies the first place in an enumeration of the natural re- 

 sources of Vermilion county. Two heavy seams underlie the larger part of 

 the southern half of the county, both of which could be worked, at depths 

 varying from nothing up to probably nowhere more than three hundred and fifty 



