68 GEOLOGY OF ILLINOIS. 



Polyphemopsis per-acuta. The chocolate-brown calcareous sandstone 

 below it contains a peculiar group of fossils, among which are Myalina 

 ampla, Aviculapecten occidentalism Avicula longispina, Pinna per-acuta, 

 Schizodus Alpinus ? JSdmondia Nebrascensis, Allorisma sub-cuneata, Bel- 

 lerapfton- crassus, Nati&ypsis Pricei ? Platyceras Nebrascensis, Productus 

 Prattenianus, and some other undetermined forms. This bed is found at 

 Garmi in the bed of a small branch south of the town containing the 

 same group of fossils. 



About three-quarters of a mile from New Haven north on Rock creek, 

 the beds numbered from two to ten of the foregoing section are well 

 exposed, and a fair quality of thin bedded micaceous sandstone is quar- 

 ried for building purposes. From this point to Garmi by the road on 

 the west side of the river the country is quite broken, and frequent 

 outcrops of sandstone and shale maybe seen in the hill sides and in the 

 banks of the small streams. On Grindstone creek, seven miles south 

 of Carmi, a bed of sandstone in rather even beds is exposed on a small 

 branch running into the main creek from the south-west. The beds 

 exposed are from twelve to fifteen feet in thickness, and the rock has 

 been quarried for building stone, and some grindstones have also been 

 made from it. Most of the beds are in tolerably even layers, but some 

 portions of the mass show a more or less concretionary structure. 



At Carmi we have a repetition of the same beds found in the vicinity 

 of New Haven, with the upper part of the section better exposed, but 

 only extending downwards to No. 5 of the section seen near New Haven, 

 the lower part of that section being here below the level of the Little 

 Wabash. Commencing with the sandstone to be seen in the north part 

 of town, above the dam, and descending from thence along the river 

 bluffs to the small creek just south of the town, we have the following 

 section : 



Ft. In. 



No. 1. Sandy shales and some sandstone in even beds 12 



No. 2. Clay shales 16 to 18 



No. 3. Two thin coats, parted by a foot or more of clay shale 1 to 1 6 



No. 4. Brown sandstone, quarry rock 8 to 10 



No. 5. Band J of cinnamon-brown shale, "with Posidonias 2 



No. 6. Dark clay shale 1 



No. 7. Gray sandy shales, passing downward into clay shale, Tvith iron stones 18 to 20 



No. 8.* IFerro-calcareous chocolate-brown sandstone, with fossils 1A to 2 



The lower bed of the above section was only partially exposed in the 

 bed of the creek, where it presents the same general appearance, and con- 

 tains the same group of fossils as were obtained from No. 5 of the section 

 near New Haven. I was unable to find more than a partial exposure 

 of it in the vicinity of Garmi. The brown sandstone No. 4 of the above 

 section contains numerous specimens of broken plants, is somewhat 



* This is equivalent to No. 47, of the general section of the Coal Measures, on p. 2, el seq. 



