218 PALEONTOLOGY OF THE EUREKA DISTRICT. 



the exfoliation of the shell has destroyed any finer striae that may have 

 existed. 



This is essentially a Devonian type, approaching such forms as Spiri- 

 fera Marcyi, S. macronata (Pal. N. Y., vol. iv), in their dorsal valves; unfor- 

 tunately there are no specimens of the ventral valve in the collections. 



Formation and locality. Lower portion of the Lower Carboniferous 

 limestone in canon directly south of a small conical hill on east side of 

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



Subgenus SPIRIFERINA D'Orbigny. 



Spiriferina cristata Schlotheim. 

 Plate xviii, tigs. 12, 13. 



Terebratulites cristatm Schlotheim, 1810. Beitr. z. Naturg. d. verst. in Akademie der 



Weisseuschaften zu Miinohen, pi. i, fig. 3. 



Spirifera octoplicatus Sowerby, 1827. Miu. Coil., p. 120, pi. 562, tables 2, 3, 4. 

 Spirifer octoplicata? Hall, 1852. Stansbnry's Expd. Great Salt Lake, p. 409, pi. iv, 



figs. 4 a, b. (Not S. octopllcaius Sowerby.) 



Kentuckensis Shumard, 1855. Geol. Surv. Missouri, vol. i, pt. 2, p. 203. 

 Kentuckensis Hall, 1856. Pacific Eailroad Rep., vol. iii, p. 102, pi. ii; figs. 10, 



11. 

 spinosus Norwood & Pratten, 1855. Jour. Acad. Nat. Sci. Philad., vol. iii, p. 



71, pi. ix, figs. 1 a-d. 



spinosus Hall, 1858. Geol. Surv. Iowa, vol. i, pt. 2, p. 706, pi. xxvii, figs. 5o-c. 

 Spiriferina octoplicata Davidson, 1862. Quart. Jour. Geol. Soc. London, vol. xviii, p. 



29, pi. i, figs. 12-13- 

 Spirifera Kentuckensis var. propatulus Shuinard, 1866. Trans. St. Louis Acad. Sci., 



vol. ii, p. 409. 

 laminosus Geinitz, 1866. Garb, und Dyas in Nebraska, p. 45. (Not S. lami- 



nosus McOoy.) 

 Spiriferina Kentuckensis Meek, 1872. U. S. Geol. Surv. Nebraska, p. 185, pi. vi, figs. 



3 a-d; pi. viii, figs. 11 a, b. 

 spinosa f Derby, 1874. Bull. Cornell University, vol. i, pt. 2, p. 23, pi. vi, 



figs. 8, 13, 14. 



Kentuckensis White, 1875. Expl. and Suiv. West 100th Meridian, vol. iv, 

 pt. 1, p. 138, pi. x, figs. 



Characteristic specimens of this species occur in the lower and central 

 portions of the Carboniferous rocks of the district, and in the upper strata 

 they are associated with a form that is typical of S. spinosa, of the Chester 

 limestone of .Illinois. This same association also occurs at Coal Hill, in the 



