841 



Ptycho, 



Ptycopteria 



Wrongly named Avicula ? on 



page 71 above. (R. P. Whitfield's corrections, Jan. ,1889.) 

 Ptychodus calceolus, {Rinodus calceolus^ Newb. & 



Worthen, Pal. Illinois, Vol. 2, 1866, Hamilton.) Pal. Ohio, 

 Vol. 2, 1875, page 59, plate 59, fig. 13, a, S, naUiral size^ side 

 view, upper surface, and cross section of a ChimceraAike fish- 

 tooth, from Hamilton strata at Davenport, Iowa; probably 

 Rinodus calceolus of Geol. Illinois, Vol. 2, plate 10, fig, 10, 

 changed to P. calceolus^ Geol. 111., Vol. 374; but longer and 

 narrower, and crown surface raised instead of depressed ; but 

 may be the diff*erence between the upper and lower teeth fit- 

 ting into each other. VIII c. 



Ptyctodus {Rinodus) calceolus, Newberry and Worthen, 

 VIllC . ... Pl^^^j.lO 



Geol. 111., Vol. 2, 1866, page 106, plate 10, figs. 10, 10 a, J, 

 crown side and profile of the tooth ; c^ magnified portion of 

 the triturating surface. Hamilton group, VIII c, 



Ptyonius marshii, Cope. ( Colosteus marshii,) Pal. Ohio, 

 Vol. 2, 1875, page 375, plate 27, fig. 6, twice natural size ; plate 

 28, fig. 3, natural size. Some of the Coal measure reptiles 

 called by Cope Sauropleura (Proc. Acad. Nat. Soc. Phila., 



