1888.] NATURAL SCIENCES OF PHILADELPHIA. 231 



Spirifera rockymontana Marcou. 



Spirifer rochymontanus Mavcou, 1858. Geol. N. A., p. 50. 



Spirifer opirmis Hall, 1858. Geol. Iowa, vol. I, pt. II, p. 711. 



Spirifer subventricosus McChesney, 1860. Disc. New Palae. Fos. 

 p. 44. 



Pioneei' mine : three specimens. This and S. opimus Hall are 

 unquestionably synonymous ; and though both names were proposed 

 the same year, Marcou's has priority as has been shown by White 

 (^Vide under Betziamormoni). McChesney in 1860 described this 

 form as Spirifer subventricosus, but in the revision of his first paper 

 he makes his species synonymous with Hall's S. opimus. 



Spiriferina kentuckensis Shumard. 



Spirifer kentuckensis Shumard, 1855. Geol. Sur. Missouri, p. 203. 



Spiriferina kentuckensis Meek, 1872. U. S. Geol. Sur. Neb., p. 

 185. 



Pioneer mine ; two specimens. This species is quite common in 

 the calcareous strata of the middle coal measures of the same locality. 



Athyris subtilita Hall. 



Terebratula subtilita Hall, 1852. Stans. Exp. Gt. Salt Lake, p. 

 409. 



Athyris subtilita Newberry, 1861. Ives Exped. Colorado River 

 p. 126. 



Not common; in fact, brachiopods are comparatively rare in thp 

 lower coal measures of the region under consideration, and with two 

 exceptions the species are represented by few examples. In the 

 limestones of the middle coal measures this species is quite abundant, 

 and often attains a large size. As is well known it has a wide 

 geographical and vertical distribution, being found from the Appa- 

 lachian to the Rocky Mountain regions ; it also occurs in the sub- 

 carboniferous of Europe and India. In all probability several species 

 described from the subcarboniferous of this country Avill prove 

 synonymous with this form. In North America its vertical range 

 would then extend from the subcarboniferous through the coal 

 measures into the permian. 



Eetzia mormoni Marcou. '^ 



Terebratula mormonii Marcou, 1858. Geology N. A., p. 51. 

 Retzia punctilifera Shumard, 1858. Trans. St. Louis Acad. Sci.^ 

 vol. I, p. 220. 

 • Retzia mormonii Meek and Hay den, 1859. Proc. Acad. Nat, 

 Sci. Phila., p. 27. 



