DESCRIFTIONS OF SPECIES. 311 



Platyceras paralium White and Whitfield? 



1862. Platyceras paralium. White and Whitfield, Boston Soc. Nat. Hist., Proc, vol. 8, p. 302. 



Chemung group: Burlington, Iowa. 

 1865. Platyceras paralium. Winchell, Acad. Nat. Sci. Philadelphia, Proc, p. 131. 



Lithographic limestone: Clarksville, Mo. 



1888. Platyceras sp. (cf. P. paralium). Herrick, Sci. Lab. Denison Univ., Bull., vol. 3, p. 92, pi. 1, fig. 



23 (fig. 22?). 

 AVaverly group: Licking County, Ohio. 



1889. Platyceras paralium. Keyes, Acad. Nat. Sci. Philadelphia, Proc, p. 294. 

 Kinderhook group: Burlington, Iowa. 



1890. Capulus paraUus. Keyes, Am. Geol., vol. 6, p. 9. 



1890. Capulus paralius. Keyes, Acad. Nat. Sci. Philadelphia, Proc, p. 166, pi. 2, figs, la, b. 



Kinderhook beds: Des Moines and Marshall counties, Iowa; Lodi, Ohio. 

 189.5. CapxUus paralium. Keyes, Missouri Geol. Surv., vol. 5, p. 174, pi. 53, figs. la-d. (Date of 

 imprint, 1894. ) 



Chouteau limestone: Sedalia, Mo. 



Burlington limestone: Louisiana, Mo. 



The material from Colorado consists of three specimens from as many localities 

 in the San Juan region, and it occurs entirely in the form of internal casts. These 

 .show a loosely coiled, laterally compressed shell, without anj- traces of longitudinal 

 plications. It is the form which, occurring in the Madison limestone of Yellowstone 

 Park, was briefly described in n^v report i^pon the Madison fauna, as Platyceras 

 form d. As pointed out in that place, a shell of this type has been figured by Keyes 

 under the name of Capulus jjaralius," although it seems to differ rather widely from 

 the type specimen of that species represented bj^ fig. 1« of the same plate. The 

 Colorado material, while attaining a size considerably^ greater than that from 

 Yellowstone Park, is still not quite as large as shown in fig. Id. 



Locality and horizon. — San Juan region (stations 2381, 2382, 2385); Ouray 

 limestone. 



ORTHONYCHIA Hall, 1843. 



Orthonychia FORMOSA Kcyes? 



1888. Platyceras Jarmomm. Keyes, Am. Phil. Soc, Proc, vol. 25, p. 242, pi. — , figs. 8, 9. 



Kinderhook group: Marshall County, Iowa. 

 1890. Capulus formosas. Keyes, Am. Geol., vol. 6, p. 9. 

 1890. Capulus formosus. Keyes, Acad. Nat. Sci. Philadelphia, Proc, p. 164, pi. 2, fig. 8. 



Kinderhook beds: Marshall County, Iowa. 

 1892. Orthonychia formosum. Keyes, Am. Geol., vol. 10, p. 276. 



1895. Orthonychia formosum. Keyes, Missouri Geol. Surv., vol. 5, p. 189, pi. 53, fig. 2. (Date of 

 imprint 1894. ) 



Kinderhook group: Marshall County, Iowa. 



Burlington limestone: Louisiana, Mo. 



o Missouri Geol. Surv., vol. 5, 1894, pi. 53, fig Id. 



