48 BRAOHIOPODS. 



various times, a variety of names, White, who has carefully 

 examined specimens from the type locality, has no hesitation 

 in referring the shell commonly called P. pratteniawus to 

 d'Orbigny's species. Until quite recently no American writ- 

 ers, with the exceptions of Owen and Marcou, noted the iden- 

 tity of the two shells. It would appear, therefore, that P. 

 prattenianus Norwood & Pratten is actually a synonym of P. 

 cora ; as is probably also P- hildrethianus of the same authors. 

 The other titles given in the synonymy have already been 

 discussed at length by Meek. 



Productus symmetricusMcCHESNEY. 



Plate xxxvi, figs. 2a-b. 



Productus symmetricus McChesney, 1860: Desc. New Pal. Foss., p. 35. 

 Productus symmetricus McChesney, 1867: Trans. Chicago Acad. Sci., vol. 



I, p, 25, pi. i, figs. 9a-b. 

 Productus symmetricus Meek, 1872: U. S. Geol. Sur. Nebraska, p. 167, pi. 



v, figs. 6a-b; pi. viii, fig. 13. 



Similar to P. nebrascensis, but somewhat flatter ; no mesial 

 sinus ; concentric folds much smaller, spines fewer, in single 

 instead of double rows. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Productus nebrascensis OWEN. 



Plate xxxvii, figs. 3a-c. 



Productus nebrascensis Owen, 1852 : Geol. Sur. Iowa, Wisconsin and Min- 

 nesota, p. 584, pi. v, fig. 3. 

 Productus rogersi Norwood & Pratten, 1854: Jour. Acad. Nat. Sci., Phila., 



(2), vol. Ill, p. 9, pi. i, figs. 3a-c. 

 Productus rogersi Hall, 1856: Pacific K. R. Kept., vol. Ill, p. 104, pi. ii, 



figs. 14, 15. 

 Productus norwoodi Swallow, 1858: Trans. St. Louis Acad. Sci., vol. I, 



p. 182. 



Productus asper McChesney, 1860: Desc. New Pal. Foss., p. 34. 

 Productus wilberanus McChesney, 1860: Desc. New Pal. FOES., p. 36. 

 Strophalosia horrescens Geinitz, 1866: Carb. und Dyas in Nebraska, p. 81. 



(Not Murchison.) 

 Productus nebrascensis McChesney, 1867: Trans. Chicago Acad. Sci., vol. 



I, p. 24, pi. i, fig. 7. 

 Productus wilberanus McChesney, 1867: Trans. Chicago Acad. Sci., vol. I, 



p. 28, pi. i, fig. 8. 



