76 The Middle Devonian Deposits of Maryland 



Three miles northeast of Oldtown where the road to Green Eidge crosses 

 the iron bridge over Town Creek, is an excellent outcrop of Hamilton 

 shales shown in the highway cut on the western bank of the creek. The 

 shales are rather coarse, somewhat arenaceous, bluish in color, some of 

 them weathering to a buff and very fossiliferous, large numbers of 

 Spirifer mucronatus (Conrad) occurring associated with other species. 

 Some of the layers in the upper part of the exposure contain numerous 

 specimens of Spirophyton. The other most abundant species are Tropido- 

 leptus carinatus (Conrad) and Chonctes. The number of species is not 

 large but it is a magnificent locality for specimens of Spirifer mucronattis 

 (Conrad). The complete list obtained at this locality is as follows: 

 Stropheodonta (Leptostrophia) perplana (Conrad), Chonetes mucro- 

 natus Hall, Chonetes scitulus Hall (some of the large forms), Chonetes 

 setiger (Hall), Chonetes lepidus Hall, Chonetes vicinus (Castelnau) 

 (some of these specimens have very much the outline of the gibbous 

 specimens figured in the New York report as Chonetes gihhosus which is 

 a synonym of Chonetes defiectus = vicinus) , Camarotoechia congregata 

 (Conrad), Eunella lincldaeni Hall, Tropidolepttts carinatus (Conrad) 

 (medium-sized specimens abundant in some of the blocks), Cyrtina 

 hamiltonensis Hall, Spirifer mucronattis (Conrad) (abundant and excel- 

 lent specimens of the mucronate form ; some of the layers of rock 

 composed largely of shells of this species), Spirifer granulosus (Conrad), 

 Ambocoelia umbonata (Conrad), Athyris spiriferoides (Eaton), (?) 

 Meristella sp., NuciilUcs ohlongatus Conrad (internal impression), 

 Pterinea flabellum (Conrad), Actinopteria sp., Aviculopecten cf. princeps 

 (small, imperfect specimen), Pleurotomaria (Bembexia) sulcomarginata 

 Conrad, Bellerophon sp., Styliolina fissurella (Hall), Tentaculites bellulus 

 Hall, Homalonotus dehayi (Green). 



The fauna is that of the Hamilton and the appearance of the rocks 

 is almost identical with that of similar shales in the Hamilton of New 

 York, to which stage these shales belong. 



By the highway leading west from Oldtown and opposite the church, 

 are outcrops of olive, argillaceous shales, with an occasional thicker mealy 

 laver, Avhich weather to a buff color and readilv disintograto into soil. 



