280 GENEKAL GEOLOGY. 



creek and Long branch, in Guthrie county, and near Adel, 

 Dallas county, the bed has afforded a few species of fossils. 

 In its lower portion at the former locality, Myalina perat- 

 tenuata, H emipronites crassus, (?) and obscure plant remains 

 occur. At Marshall's coal-mine on Long branch, Lingula 



is found in a similar position. Above this there 



is a well-marked layer which is literally crowded with the 

 exuviae of a minute Ostracoid crustacean, resembling, if not 

 identical with, Beyrichia fcetoidea. On Hickory branch, near 

 Adel, the same fossil occurs in equivalent exposures, besides, 

 a minute Gasteropoda undetermined and obscure plant 

 remains. 



No. 35. Brown, fine-grained, heavy bedded and shaly 

 sandstone. From a few inches to thirty-five feet in thick- 

 ness, although its normal thickness is about eight feet. The 

 remarkable thickening of this stratum forcibly brings to 

 mind similar irregularities in the arenaceous deposits of the 

 Lower coal formation. The least observed thickness .of the 

 bed is seen on Sugar creek, Dallas county, where it is repre- 

 sented by two thin quartzose layers, together not more than 

 twelve inches thick, and charged with comminuted vegetable 

 remains. The greatest thickening of the bed occurs in Warren 

 county, where it sometimes reaches the thickness of thirty -five 

 feet, as exhibited in the exposures on Otter creek, in the 

 vicinity of Hammondsburg. The rock is usually soft, and 

 easily disintegrated from exposure. Quarries have been 

 opened in the bed at several localities in Warren and Dallas 

 counties. Those near Adel furnish a tolerable freestone. 

 In the thickened bed, it is not unusual to find large lenticular 

 masses that present the characteristics of true quartzite. 



The only organic remains known from this bed at present, 

 are a few plants : JVeuropteris, Sigillaria, Catamites. 



No. 36. Blue and yellow shales; two to eight feet. 



No. 37. Bituminous shales; one to four feet. A coal- 

 seam four to fourteen inches thick, locally occurs in the base 

 of this bed, in Guthrie and Warren counties. It has been 

 termed, for convenience of reference, the lower carbonaceous 



