BRACHIOPODA. 
225 
0. discus, 
Hall. 
* 0. eminens, 
Hall. 
. Lower Helderberg. 
* 0. oblata, 
Hall. 
. Lower Helderberg. 
* 0. tubulostriata, 
Hall. 
. Lower Helderberg. 
* 0. Cumberlandia, Hall. 
. Oriskany. 
* 0. musculosa, 
Hall. 
. Oriskany. 
* 0. alsus, 
Hall. 
* 0. peloris, 
Hall. 
. Schoharie. 
* 0. Cleobis, 
Hall. 
. Gorniferous. 
* 0. Livia, 
Billings. 
. Corniferous. 
0. Semele, 
Hall. 
. Corniferous. 
* 0, Vanuxemi, 
Hall. 
. Hamilton. 
* 0. Yanuxemi, 
var, pulchella, 
Herrick . 
. Waverly .f 
* 0. cyclas, 
Hall. 
. Hamilton. 
* 0. idonea, 
Hall. 
. Hamilton. 
# 0. Leucosia, 
Hall. 
* 0. Penelope, 
Hall. 
. Hamilton. 
# 0. solitaria, 
Hall. 
. Hamilton. 
* 0. suborbicularis, Hall. 
. Hamilton. 
* 0. Pennsylvania, Simpson . 
. Chemung. 
[?] 0. cuneata, 
Owen . 
. Devonian. 
0. Lucia, 
Billings. 
0. occasus, 
Hall. 
0. subelliptica, 
White and Whitfield 
. Waverly. 
* 0 Missouriensis, 
Swallow. 
. Choteau. 
# 0. Burlingtonensis, Hall . 
0. Dalyana, 
Miller. 
# 0. Thiemii, 
White. 
. Burlington. 
0. Clarkensis, 
Swallow . 
. Keokuk. 
* 0. Oweni, 
sp. nov. 
. Knobstone. 1 
* 0. dubia, 
Hall. 
. St. Louis. 
t There is a larger form 
of Orthis in the Waverly of Ohio, which has a very gibbous brachial 
and can not be regarded as 
identical with this variety of 0 . 
Vanuxemi. 
I The “Knobstone group” of Owen, in Kentucky and the southern part of Indiana, in its lowest mem¬ 
bers, has been generally regarded as of the age of the Waverly of Ohio. Its upper member has been 
paralleled with the Keokuk, but the limitation between these formations is not always well defined or easily 
determined. 
