C. A. Reeds — Ilunton Formation of Oklahoma. 261 



Characteristic Species of the Chimneyhill Formation 



(Silurian). 



Oolitic member. 



Atrypa n. sp., Schuchertella sp., Rhipidomella n. sp., Cyclo- 

 nema daytonensis. 



Glauconitic member. 



Callopora magnopora, Pachydictya bifurcata, Phenopora fim- 

 briatu, Phenopora magna, Rhinopora verrucosa, Plectambonites 

 transversalis n. var., IStrophomena (?) antiquata, Cyclonema ven- 

 tricosa, Orthoceras cf. latanummulatum,llla>nns ambiguas,IUamus 

 cf. armatus. 



Pink-crinoidal member. 



Pisocrinus sp., Hommospira n. sp., Plectambonites tennesseensis 

 (cf. qulnquecostata McCoy), Spirifer radiatits, Stropheodonta 

 corrugata, Triplecia n. sp. (cf. waldronensis), Whitjieldella sp., 

 Delthyris n. sp., Conocurdium sp., Hyolithes n. sp., Lophospira 

 sp., Calymene sp., Cyphaspis clintonensis, Dalmanites arkansus, 

 Illamus 2 sp., Lichas n. sp., Odontopleura arkansana, Proetus 

 corrugatus ?, Proetus determinants ?, Sphmrexochus sp. 



Oolitic and glauconitic members. 



Orthis flabellites. 



Glauconitic and pink-crinoidal members. 



Stephanocrinus elongatus, Conoeardium sp., Strophostylus 

 cyclostomus, Orthoceras rectum, Dalmanites sp. 



Oolitic, glauconitic and pink-crinoidal members. 



Streptelasma cf. bilateralis, Clorinda n. sp., Dalmanella ele- 

 gantula, Hebertella fausta, Platystrophia biforata, Triplecia cf . 

 ortoni, Hormotoma sp., Dalmanites werthneri, Illoenus cf. day- 

 tonensis. 



Henryhouse shale (Silurian). 



This formation varies from to 223 feet in thickness. The 

 thickest exposures occur in the Lawrence anticline on Chimney- 

 hill creek in the northeast corner of the Arbuckles and again 

 in the south limb of the Arbuckle anticline along the south- 

 west border of the mountains from Springer to Poolville (Elk). 

 Good outcrops may be seen on Henryhouse creek 3 miles east 

 of Woodford. The formation takes its name from this creek. 

 In the central part of the mountains in the vicinity of 

 Dougherty the formation is not so thick and on the eastern 

 side of the Arbuckles from Canyon creek south to Bromide 

 (Sulphur Springs) it is altogether wanting. 



