Marylaxd Geological Survey 71 



Total 



Thick- thick- 

 iit'ss. ness. 



the Williams Road.^ Succeeding the shales is a narrow covered 

 zone on the highway and then an exposure of about 75 feet of 

 argillaceous shale weathered to a brownish tint is reached which 

 is in the Genesee at the base of the Jennings formation. This 

 is followed by the greenish argillaceous shales with thin sand- 

 stones of the Woodmont member of the Jennings which continue 

 down the western slope of the hill 65 1281 



The following species were collected from the Hamilton beds of the 

 above section: Lingulella (?) paliformis Hall, Lingula cf. nuda Hall, 

 Pholidops harrnltoniae Hall (?) , Stropheodonta (Leptosti-ophia) perplana 

 (Conrad), Schuchertella variabilis Prosser, Chonetes mucronatus Hall, 

 Chonetes coronatus (Conrad), Chonetes scitulus Hall (?), Chonetes 

 setiger (Hall), Chonetes lepidus Hall, Rhipidomella cyclas Hall (?), 

 Orthis sp. (small forms), Camarotoechia congregata (Conrad), Camaro- 

 toechia prolifica Hall, Liorhynchus laura (Billings), Tropidoleptus cari- 

 natus (Conrad), Spirifer mucronatus (Conrad), Spirifcr audaculus (?) 

 (Conrad), Ambocoelia umbonata (Conrad), Anoplotheca (Coelospira) 

 acutiplicata (Conrad), Vitulina pustulosa Hall (?), Phthonia sectifrons 

 (Conrad), Grammysia arcuata (Conrad), Tellinopsis suhemarginata 

 (Conrad), Nuculites triqueter Conrad, Palaeondlo constricta (Conrad), 

 Modiella pygmaea (Conrad), Modioniorpha concentrica (Conrad) (?), 

 Cydonema liratum Hall var. grahaui Prosser, Homalonotus dekayi 

 (Green). 



In general, it may be said, on comparing tlie rocks of the Williams 

 Eoad section with the one at 21st Bridge that they are weathered to a 

 much greater extent and a considerable part are much more yellowish. 

 The limestones of the Onondaga shales were not found on the Williams 

 Eoad nor as many specimens of Liorhynchus Umitare (Vanuxem) as 

 in the Baltimore and Ohio E. E. cut at 21st Bridge. Again, the very 

 fossiliferous zone of the Hamilton as exposed in the cut near the 21st 

 Bridge was not recognized while the sandstones of the upper part of the 

 Williams Eoad are not shown in the southwestern section which, possibly, 

 does not extend as high in the Eomney formation. 



' Dr. Swartz's estimate of 157 feet for the thickness of the Onondaga member 

 is used in this estimate of the thickness of the Romney formation. 



