388 The Upper Devonian' Deposits of Maryland 



characteristic Chemung species Spirlfcr dlsjunctus Sowerby is common 

 and in phices there are beautifully preserved specimens. There is more 

 or less reversal of dip in these outcrops, so that none of them are favor- 

 able for determining the thickness of the rocks. One of these sections 

 follows the road northeast from Mountain Lake Park, crosses Ness Lick 

 Kun, then the hill by the Mitchell house and continues to Altamont. 



Just after crossing the western branch of Ness Lick Run, to the 

 north of Mountain Lake Park, above the point at which the upper Deer 

 Park Road from Oakland joins the Mountain Lake Park Road, are 

 olive argillaceous shales in the gutters by the side of the road and plenty 

 of loose, argillaceous, greenish sandstones. In some of these pieces are 

 fossils, the most common of which is Ambocoelia umbonata (Conrad), 

 Cyrtina sp. was also found. The soft argillaceous shales weather into 

 clay. There is an occasional piece of quartz conglomerate but the 

 pebbles are quite small. The rocks are exposed in the gutters almost to 

 the top of the hill and are mostly olive to yellowish-green shales. Some 

 of the layers are slightly reddish and others vary from a light gray to 

 almost white. 



Near the base of the ridge just west of the Ness Lick Run branch, 

 at the locality just described, are quite large blocks of grayish conglom- 

 erate containing some flat white quartz pebbles. Some of these blocks 

 occur in the gutter on the upper Deer Park Road but a short distance 

 above its junction with the Mountain Lake Park Road while to the north 

 of it they have the appearance of a broken down ledge. 



Blocks of conglomerate occur to the south of the locality just described 

 on the road from Hotel Dennett in the northwestern part of Mountain 

 Lake Park to Oakland. There are also large blocks of conglomerate on 

 the western side of the small draw not far west of Hotel Dennett appar- 

 ently the same as those just described to the west of Ness Lick Run. 

 From the blocks found at other localties about on the line of strike with 

 this one it appears that there is a stratum of this conglomerate in the 

 Chemung rocks on the western side of the anticlinal axis which is light 

 gray in color and contains numerous quartz pebbles part of which at least 

 are flat, and on the jointing surfaces of the blocks are broken directly 



