EXPLANATION OF PLATE II 



All figures arc enlarged four diameters except 4b and 9 which are enlarged eight 

 diameters. 



Figs. l-3b. Yvania adamsi (Worthen) p. 30 



Specimens from Peoria County. 



Figs 4a-5c. Yvania subcon strict a ( Meek and Worthen) p. 32 



4a-5c. Specimens from Peoria County. 

 4b. Upper surface of whorl (x8). 



Figs. 6-8b. Yvania gii-tordi (Worthen) p. 36 



Specimens from Peoria County. 



Fig. 9. Yvania inclinata Weller. n. sp p. 15 



Holotype. Upper surface of whorl (x 8). 



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