384 CAUnoNIKKROUS KOKMATKIN^i AND FATTNAK OF TOLOKADo. 



IKTii. X/)i/-//'cr rocki/iiioiiliimix. Wliilo, I'owellV Rupl. Geol. VinUi Mcmntains, p. IK). 



Lower Aubivy jiroup: Si)lit ^Mimntain t'linyon and near I'',clio Park, I'tah. 



Upper Antiri'v f;roiip: Beehive I'liiiit, near IlorHeslioo Canyon, Utah. 

 1S77. SpiHjrr { Trii/iiiiolirtii) opiinun.' Meek, U. S. (JeoL lO.xpl. 40th Par., Kept., vol. 4, p. 88, pi. 9, fig. G. 



C'arlioniferous limestone: Six inilen south of Promontory Station, Promontory Mountains, Kail- 

 road Canyon, Moleen Peak; Mnunt Nebo in Utah; Fossil Hill. While Piiie district. 

 IS79. Sjiirifn- fi)i-l.-i/iii(iiil(iiiiis. Smith, Am. Phil. Soc, Proc, vol. 35, p. 32. 



Lower Coal Measures; White County and Crawford County, Ark. 



See also SpiHfer keotuk. 

 1883. Spirifrra opima. Hall, Kept. New York State (ieol. for 1882, pi. (31) 5li, figs. 4-7. 



Coal Measures: Iowa; Brazil, South America, 



1887. Spin/era upiiii'i. Herrick, Sei. Lai). Denison Univ., Bull., vol. 2, p. 44, pi. 2, fig. 23. 

 Coal jNIeasures; Flint Ridge, Ohio. 



1888. iSpirijhn wckiimontana. Keyes, Acad. Nat. Sci. Philadelphia, Proc, p. 231. 

 Lowei- Coal Measures; Des Moines, Iowa. 



1891. Spirlfeni rocki/montana .' Whitfield, New York Acad. Sci., Ann., vol. 5, p. 584, pi. 13, fig. 20. 

 Maxville limestone (Chester) : Newton ville, Ohio. 



1893. Splrifer opimuK. Hall and Clarke, Pal. New York, vol. 8, pt. 2, pp. 27, 39, pi. 31, fig.-. 4-7. 



(Advance distribution in fascicles. ) 

 Coal Measures; Bomjardim, Brazil. 



1894. Spiiifer oplinus. Hall and Clarke, Int. Study of Brach., pt. 2, pi. 27, figs. 12, 13. 

 Coal jNIeasures: Iowa. 



1895. Spirifera rockyinontana. Keyes, Missouri Geol. Surv., vol. 5, p. 84. (Date of imprint 1894.) 

 Upper Coal Measures: Kansas City, Mo. 



1895. Spirifer opimus. Hall and Clarke, Pal. New York, vol. 8, pt. 2, pp. 27, 39, pi. 31, figs. 4-7. 



Coal Measures; Iowa; Bomjardim, Brazil. 

 1895. Spirifera rockymontana? Whitfield, Geol. Surv. Ohio, Kept., vol. 7, p. 471, pi. 9, fig. 20. 



Maxville limestone (Chester); Newtonville, Ohio. 

 1899. Spirifer rockymontanus. Girty, U. S. Geol. Surv., Nineteenth Ann. Kept., pt. 3, p. 578. 



Upper Coal Measures: McAlester quadrangle; Atoka quadrangle. 



From a study of Marcou's figures, I am inclined to believe that he had in hand 

 two distinct species when Spirifer rockymontanus was described. Figs. 4:C, 4d, 

 and 4e clearly represent a shell of the type which commonljr passes under the name 

 proposed by Marcou, and which Hall described as 8p. opimus. But the larger 

 specimen figured by Marcou represents a different sort of shell. It has many bifur- 

 cating ribs, and is perhaps one of the short-hinged varieties of S;p. cwnie^-atus or its 

 allies, such as sometimes occur. I propose to restrict the name Spirifer rockymon- 

 tcmvs to shells of the type of Marcou's figures 4c, 4d, and 4e, thus retaining the 

 name in its customary significance. 



Spirifer' rockymontanus has a wide distribution, both in the Mississippi Valley 

 and the Rocky Mountains. It has been found at many stations in Colorado, but 

 seems to be especiallj' abundant in the Leadville region. Specimens having all the 

 characters of mature Sjy. rockymontanus vary much in size. There are usually five 



