30.8 



135.3 



6.6 



104.5 



35.6 



97.9 



160 The Lower Devoni.vn Deposits of Maryland 



Hkldekberg Formation 



Horizontal Vertical Total 

 Keyser Member instance thickness vertical 



feet feet thickness 



Hard blue massive limestone, the upper and lower 

 parts filled with Oypidula coeymanensis var. prog- 

 nostica. About half of this unit is concealed 260.0 15.4 150.7 



Mostly concealed. Near bottom in heavy blue lime- 

 stone occur Camarotocchia litchfieldensis, Spirifer octo- 

 costatus, etc 225.0 



Heavy dark blue limestone 155.0 



Concealed 



Heavy dark blue limestone containing at the bottom 

 Cladopora rectilineata and bryozoa 140.0 8.9 62.3 



The remainder of the section is exposed in a direc- 

 tion due west from the bottom of the above unit. 



Concealed. At the bottom of this unit there is an 

 exposure of limestone containing Spirifer vanuxemi 

 prognostica, 8. modestus, Stropheodonta Mpartita. 

 Camarotocchia litchfieldensis. Leperditia elongata.... 120.0 53.4 53.4 



Thickness of Keyser member exposed 150.7 



ToxoLowAY Formation 

 Concealed. 



A short distance west of top of section were found Thamniscus regularis, 

 Fenestella {Cydoporina) altidorsata. 



XV. Section n/^ Miles East of Rush 

 Three and one-half miles southwest of Plintstone, on the road crossing 

 Warrior Mountain and leading to Eusli, is an exposure of the lower beds 

 of the Keyser limestone on the south side of the road, beginning south 68° 

 west of the residence of Mr. George Twigg. Only the following species 

 were found in the lower portion of the section at this place : Camwrotoechia 

 litchfieldensis, Chonetcs jerseycnsis, Ehynchospira glohosa, and Spirifer 

 (cf.) vanuxemi var. prognosticus. The Tonoloway is also partly exposed 

 and the stratigraphic position and nodular character of the overlying beds 

 show that they are in the Keyser member. The section begins T30 feet 

 horizontally, east of the road which leads to the south on ^Yarrior Moun- 

 tain, opposite the residence of Mr. George Twigg. 



