FOSSILS OF THE CARBONIFEKOUS. 



213 



approaches A. Shumardana Hall (Ibid., p. 699) of the Lower Carboniferous 

 limestone. 



Formation and locality. Lower portion of the Lower Carboniferous 

 limestone on east slope of a small conical hill on the east side of Secret- 

 canon-road Canon, Eureka District, Nevada. 



BRACHIOPODA. 



Genus DISCINA Lamarck. 

 Discina Newberryi Hall. 

 Plate xviii, figs. 3 (2, 2 a?). 



Discina newberryi Hall, 1863. Sixteenth Ann. Kep. N. Y. State Cab. Nat. Hist., p. 30. 



Pal. N. Y., 1867, vol. iv, p. 25, pi. i, figs. 10 a, &, lla-c. 

 Discina ( Orbiculoidea) Newberryi Meek, 1875. Pal. Ohio, vol. ii, p. 277, pi. xiv, figs. 1 a-d. 



The Eureka shells present no features by which they can be distin- 

 guished from this species when directly compared with authentic specimens 

 from the Waverly sandstones of Ohio. 



At a little lower horizon a form of Discina occurs in a black shale that 

 may belong to this species. All the specimens are more or less distorted 

 by pressure. The two valves are shown by figs. 2, 2 a of plate xviii. 



Formation and localities. Lower portion of the Carboniferous Group, 

 Richmond Mountain and on east slope of a small conical hill on the east 

 side of Secret-canon-road Canon, Eureka District, Nevada. 



Discina nitida Phillips. 

 Plate vii, figs. 4, 4 a. 



Orbicula nitida Phillips, 1836. Geol. of Yorkshire, pt. 2, p. 221, pi. xi, figs. 10-13. 

 Discina Missouriensis Shumard, 1860. Trans. St. Louis Acad. Sci., vol. i, p. 221 (as deter- 

 mined by Meek). 



nitida Meek & Worthen, 1873. Geol. Stirv. 111., vol. v, p. 572, pi. xxv, fig. 1. 

 For description and synonoiny, see Mon. Brit. Foss. Brach. Davidson, vol. ii, p. 197. 



Well-marked examples of this species occur in the Lower Carbonifer- 

 ous limestone of Coal Hill, in the Pancake Range, and also on the west side 



