First traceable shelly horizon above the newly named Stolle Road Bed is the Girdle Road Bed, also newly named. Both beds are assigned to the Darien Center Submember of the Wanakah Shale Member of the Ludlowville Formation and lie above the Mt. Vernon Bed at the Submember's base. Girdle Road Bed contains a moderately diverse fauna and marks a change from fossil-poor gray shales below to fossiliferous gray calcareous shales above. Bed marks the first occurrence of the coral PLEURODICTYUM AMERICANUM above the Mt. Vernon Bed. The next prominent concretionary horizon above the Girdle Road Bed is referred to by Miller (1991) as Lakeview Bed (previously "NAUTILUS Bed" of Grabau, 1899). Age of the Wanakah Shale Member and all its beds is Middle Devonian.
["Submember" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). Considered informal until formally published. The rank or lithologic term should not be capitalized.]

Source: GNU records (USGS DDS-6; Reston GNULEX).