BRACHIOPODA. 225 



0. discus, IIali Lower Helderberg. 



* 0. eminens, Hall Lower Helderber";. 



* 0. oblata, Hall Lower Holderber-;. 



* 0. tubulostriiita, Hall Lower Helderberj!;. 



* 0. Cumberlandia, Hall Oriskany. 



* 0. musculosa, Hall Oriskany. 



* 0. alsus, Hall Schoharie. 



* 0. peloris, Hall Schoharie. 



* 0. Cleobis, Hall Corniferous. 



* 0. Livia, Billings Corniferous. 



0. Semele, Hall CorniCorous. 



* 0. Vanuxemi, Hall Hamilton. 



* 0. Vanuxemi, ^t t^r i , 



var. pni.hriiu. Herrick Wavcrly.f 



* O. cyclas, Hall Hamilton. 



* 0. idonea, Hall Hamilton. 



* 0. Leucosia, Hall .... Hamilton. 



* 0. Penelope, Hall Hamilton. 



* 0. solitaria, Hall Ha.milton. 



* 0. suborbicularis, Hall Hamilton. 



* 0. Pennsylvanica, Simpson Chemung. 

 [?] 0. cuneata, Owen Devonian. 



0. Lucia, Billings Devonian. 



0. occasus, Hall Waverly. 



0. subelliptica, White and Whitfield Waverly. 



* Missouriensis, Swallow Choteau. 



* 0. Burlingtonensis, Hall Burlington. 



0. Dalyana, Miller /Burlington. 



* 0. Thiemii, White Burlington. 



0. Clarkensis, Swallow Keokuk. 



* O. Oweni, sp. nov Knobstone.:]: 



* 0. dubia. Hall St. Louis. 



t There i^s a larger Ibrin of Okthis in the Wjiverly of Ohio, which has a \eiy gibbous brachial valve, 

 and can not be regarded sis identical with this variety of 0. Vamaemi. 



I The "Knobstone group" of 0wE>f, in Kentucky and the southern part of Indiana, in its lowest mem- 

 bers, has been generally regjirded as of the age of the Waverly of Ohio. Its upper member h.os been 

 paralleled with the Keokuk, but the limitation between these formations is not always well defined or easily 

 determined. 



