E.VSTMAN : CARBONIFEROUS FISHES FROM THE CENTRAL WEST. 181 



Platyxystrodus occidentalis (St. John). 



1870. Xystrodus (Z) occidentalis 0. II. St. John, Troc. Amer. Phil. Soc, Vol. XI., 



p. 436. 



1872. Xi/sfrodtis (?) occidentalis O. H. St. John, Hayden's Final Kept. U. S. Geol. 



"Surv. Nebraska, p. 244, PI. IV., Fig. 18. 



This species is founded upon a single imperfect tooth, doubtfully of this 

 genus, from the Missourian of Aspinwall, Nebraska. The general form is 

 suf'estive of Deltodus, but the coronal surface is described by St. John as 

 exhibiting the characteristic puuctations of Platyxystrodus. 



Deltodus angularis Newberry and Worthen. 

 (Plate 2, Fig. 19.) 



1806. Deltodus angularis Newberry and Worthen, Pal. Illinois, Vol. II., p. 97, PI. 



IX., Fig. 1. 

 1870. Deltodus (?) angularis O. H. St. John, Proc. Amer. Pliil. Soc, Vol. XI., p. 437. 

 1872. Deltodus (?) angularis O. H. St. John, Hayden's Final Kept. U. S. Geol. 



Surv. Nebraska, p. 244, PI. VI., Fig. 18. 

 1883. Orthopleurodus carbonarius St. John and Worthen, Pal. Illinois, Vol. VII., 



p. 192, PI. XIII., Fig. 7 (non Figs. 6, 8). 



The forms cited in the above synonymy all plainly belong to the genus 

 Deltodus, and hence we find ourselves unable to agree with St. John and 

 Worthen in their proposed union of this species with Sandalodus, on the basis 

 of three fortuitously associated teeth described by them in Volume VII. of the 

 Illinois Palaeontology. A small posterior dental plate was obtained by St. 

 John from the Missourian of Nebraska City, and the larger one shown in Plate 

 2, Fig. 19, is from the same horizon near Louisville, Nebraska. 



Fornuition and Locality. —Mhsomian; Kansas, Nebraska, Iowa, and Mis- 

 souri. Lower Coal Measures; Illinois and Indiana. 



Sandalodus carbonarius Newberry and Worthen. 



1866. Sandalodus carbonarius Newberry and Worthen, Pal. Illinois, Vol. II., p. 104, 



PI. X., Figs. 4, 5. 

 1883. Orthopleurodus carbonarius St. John and Worthen. Op. cit., Vol. VII., p. 192, 



PI. XIII., Figs. 6, 8. 

 1889. Orthopleurodus carbonarius J. P. Lesley, Kept. Geol. Surv. Penn., Vol. II., 



pp. 568, 920, PI. 4. 

 1895. Orthopleurodus carbonarius J. P. Lesley, Summary Geol. Penn., Vol. III., 



PI. LXXL 



Examples of this species determined by St. John and Worthen as " long 

 posterior teeth of the upper jaw " are reported by these authors from the 

 " Upper Coal Measure strata near Topeka, Kansas." 



