160 GA.STEROPODS. 



Straparollus planidorsatus MEEK & WORTHEN. 



Euomphalus planidorsatus Meek & Worthen, 1860: Proc. Acad. Nat. Sci., 



Phila., p. 462. 

 Euomphalus perspective Swallow, 1863: Trans. St. Louis Acad. Sci., vol. 



II, p. 98. 

 Straparollus planidorsatus Meek & Worthen, 1866 : Geol. Sur. Illinois, vol. 



II, p. 302, pi. xxiv, figs. 2a-c. 



Shell rather below medium size, planorbiform ; spire a little 

 elevated ; whorls four or five in number, flattened above, with 

 a well-defined angularity toward the peripheral margin ; regu- 

 larly rounded below, though often a slight revolving promi- 

 nence is also discernible; suture rather deeply impressed; um- 

 bilicus broad and rather deep; aperture nearly circular; sur- 

 face smooth, with occasional lines of growth. 



Horizon and localities Lower Carboniferous, Kaskaskia 

 limestone: Ste. Mary (Ste. Genevieve county). 



Straparollus catilloides (CONRAD). 



Inachus catilloides Conrad, 1842: Jour. Acad. Nat. Sci., Phila., vol. VIII, 



p. 273, pi. xv, fig. 3. 

 Euomphalus rugosus Hall, 1858 : Geology Iowa, vol. I, p. 723, pi. xxix, fig. 



14. (Not Sowerby, 1812.) 

 Serpula (Spiorbis) planorbites Geinitz, 1866 : Garb, und Dyas in Nebraska, 



p. 3, tab. i, fig. 6. (Not Munster.) 

 Straparollus (Euomphalus) rugosus Meek, 1872 : U.S. Geol. Sur. Nebraska, 



p. 230, pL vi, figs. 5-6; and pi. xi, figs. 4a-b. 

 Straparollus (Euomphalus) subrugosus Meek & Worthen, 1873 : Geol. Sur. 



Illinois, vol. V, p. 607, pi. xxix, fig. 11 . 

 Euomphalus rugosus White, 1884: Geol. Sur. Indiana, 13th Ann. Kept., 



p. 161, pi. xxxik, figs. 11-12. 



Euomphalus rugosus Keyes, 1888: Proc. Acad. Nat. Sci., Phila., p. 241. 

 Straparollus catilloides Keyes, 1891: Proc. Acad. Nat. Sci., Phila., p. 253. 

 Straparollus catilloides Keyes, 1891: Johns Hopkins Univ. Circulars, vol. 



XI, p. 29. 



Shell small, planorbiform, concave above and below ; 

 whorls five in number, increasing gradually in size, obliquely 

 flattened on the periphery, which is bordered on each side by 

 a narrow rounded ridge, and on the upper and lower sides. 

 Aperture trapeziform outside, circular inside. Surface smooth, 

 but often strongly marked by lines of growth. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Atchison, Kansas City. 



