CEPHALOPODS. 223 



curve on each side, particularly between the middle and outer 

 angles, and crossing the broadly flattened dorsum with a strong 

 backward curve; surface with distinct lines of growth, which 

 curve strongly backward like the septa, in crossing the outer 

 side. ( Meek.) 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Nautilus winslowi MstK & WORTHEN 

 Plate Ivi, fig. 2. 



Nautilus winslowi Meek & Worthen, 1870: Proc. Acad. Nat. Sci., Phila., 

 p. 50. 



Nautilus ( Tremnochilus ) winslowi Meek & Worthen, 1873: Geol. Sur. Illi- 

 nois, vol. V, p. 609, pi. xxxii, figs. 2a b. 



Nautilus winslowi White, 1884 : Geol. Sur. Indiana, 13th Ann. Kept., pt. ii, 

 p. 165. pi. xxxvi, tigs. 1-2. 



Nautilus winslowi Keyes, 188S : Proc. Acad. Nat. Sci., Phila., p. 242. 



A large robust form, with broad umbilicus and flattened 

 periphery, toward the margins of which on each side is a row 

 of prominent tubercles. 



Horizon and localities Upper Carboniferous, Upper Coal 



Measures: Lexington (Lafayette county.) 







Nautilus forbesianus MCCHESNEY. 

 Plate Ivi, figs. 4a-b. 



Nautilus forbesianus McCbesney, 1860: Desc. New Pal. Foss., p. 63. 

 Nautilus forbesianus McChesney, 1867: Trans. Chicago Acad. Sci., vol. I, 



p. 50, pi. iii, fig. 4. 

 Nautilus forbesianus White, 1884 : Geol. Sur. Indiana, 13th Ann. Rep., pt. 



ii, p. 165, pi. xxxvi, figs. 3-4. 

 Tremnochilus forbesianus Hyatt, 1891: Geol. Sur. Texas, 2nd Ann. Rep., 



p. 330. 



Shell rather small, heavy ; volutions rounded, with a series 

 of prominent, distant nodes on each side toward the periphero- 

 lateral border. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



