72 Trilobites. 



Trilohites. — In examining, a few miles west of this place, in the 

 same range of hills, the fossil contents of a rock, which is fine 

 grained, but rather loose in texture, and tinged brown with the oxide 

 of iron, I discovered, in a few minutes, no less than three imperfect 

 and broken Trilobites, which are the first I have seen in place in the 

 valley of the Ohio. A drawing of the most perfect specimen is 

 given at Fig. 13. Portions of the abdomen are most common. 



Fig. 13. 



Description. — Breadth, one inch ; length, about one inch and a 

 half; diameter, half an inch. Tergum or intermediate lobe thick ; 

 one third thicker than the flanks, and more convex. Lobes deeply 

 sculptured or furrowed, the whole of which are equal in size in all 

 the lobes ; encircled at the base with a flat horizontal zone, one 

 eighth of an inch wide. Coated with brown oxide of iron, as are 

 most of the reliquiae of this deposit. No thorax or head found. 

 The Trilobites are in conipany with innumerable relics of radiated 

 Encrini, and thin, delicate, fine rayed Producti, similar to those found 

 in the vicinity of the transition limestone, near the hot springs in 

 Bath County, Virginia. Some very large and perfect Spiriferi, more 

 than two inches in width, are found in the more compact and deeper 

 seated deposit below. They are more deeply grooved and stronger 

 marked than those from "Flint Ridge." I have also a very perfect 

 bivalve from the same locality, which looks like a small, elongated 

 Mya. As we descend deeper towards the base of the hills, these 

 remains become more rare, the rock is finer grained, of a rich brown 

 color, and furnishes a beautiful material for tomb-stones and chimney- 

 pieces, and other ornamental work. The finest variety is singularly 

 spotted with small dark specks, all through the stone ; it looks, when 

 polished, as if it had been sprinkled with some dark liquid stain. 

 It is a very curious fact, that a similar rock is found in Illinois, near 



