196 aASTEROPODS. 



Strophostylus ? car ley ana (HALL) 



Natica carleyana Hall, 1856: Trans. Albany Inst., vol. IV, p. 31. 



Naticopsis carleyana Miller, 1877: Cat. Am. Pal. Foss., p. 154. 



Naticopsis carleyana Whitfield, 1882: Bui. American Mus. Nat. Hist , No, 



3, p. 71, pi. viii, figs. 26-27. 

 Naticopsis carleyana Hall, 1883 : Geol. Sur. Indiana, 12th Ann. Kept., p. 



369, pi. xxxi, figs. 26-27. 



A minute shell, consisting of about three whorls ; and with 

 inner lip greatly thickened. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Alton, Illinois. 



Strophostylus nana MEEK & WORTHEN. 



Platystoma nana Meek & Worthen, 1860: Proc. Acad. Nat. Sci., Phila., 



p. 463. 

 Naticopsis nana Meek & Worthen, 1866 : Geol. Sur. Illinois, vol. II, p. 



365, pi. xxxi, fig. 4. 

 Naticopsis nana White, 1884: Geol. Sur. Indiana, 13th. Ann. Rep., pt. 



ii, p. 162, pi. xxxvi, figs. 6-7. 

 Naticopsis nana Keyes, 1891: Proc. Acad. Nat. Sci. , Phila., p. 257. 



Shell very small, globose, slightly wider than high ; volu- 

 tions three or four in number, increasing rapidly in size ; body 

 whorl very large and ventricose, spire low and small; suture 

 deep. Aperture large, broadly ovate. Surface marked by 

 fine lines of growth, which pass into small regularly arranged 

 elevations near the suture. 



Horizon and localities - Upper Carboniferous, Upper Coal 

 Measures : Clinton ( Henry county ), Kansas City. 



A recent examination of a good series of the form under 

 consideration from Iowa, appears to indicate that the shell is 

 not a true Naticopsis, as was thought by Meek & Worthen, and 

 as is generally understood, but belongs more properly to HalFs 

 genus Strophostylus as recently amended. As already stated 

 in another place, it has been deemed advisable to modify some- 

 what the limits of Naticopsis, and apply the name only to those 

 shells having a close resemblance to the typical species which, 

 without exception so far as is known, ha^e a more or less well- 

 defined series of short, transverse ridges near the sutural line. 



