236 VERTEBRATES. 



Ctenacanthus excavatus ST. JOHN & WORTHEN. 



Ctenacanthus excavatus St. John & Worthen, 1875: Geol. Sur. Illinois, 

 vol. VI, p. 428, pi. xv, figs. 4a-d. 



Horizon and localities. Lower Carboniferous, Keokuk 

 limestone: LaGrange (Lewis county). 



Ctenacanthus keokuk ST. JOHN & WORTHBN. 



Ctenacanthus keokuk St. John and Worthen, 1875: Geol. Sur. Illinois, 

 vol. VI, p. 427, pi. xv, figs. 8a-e. 



Horizon and localities. Lower Carboniferous, Keokuk 

 limestone: Boonville (Cooper county), LaGrange (Lewis 

 county ). 



Ctenacanthus pugiunculus ST. JOHN & WORTHEN. 



Ctenacanthus pugiunculus St. John & Worthen, 1875: Geol. Sur. Illinois, 

 vol. VI, p. 430, pi. xxi, figs. 9a-c. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Ctenacanthus gracillimus NEWBERRY & WOKTHEN. 



Ctenacanthus gracillimus Newberry <fc Worthen, 1866 : Geol. Sur. Illinois, 



vol. II, p. 126, pi. xiii, fig. 3. 

 Leptacanthus ? occidental Newberry & Worthen, 1866 : Geol. Sur. Illinois, 



vol. II, p. 116, pi. xii, fig. 2. 

 Acondylacanthus occidentahs St. John & Worthen, 1875 : Geol. Sur. Illinois, 



vol. VI, p. 433. 

 Ctenacanthus gracillimus St. John & Worthen, 1883: Geol. Sur. Illinois, 



vol. VII, p. 238, pi. xxiv, fig. la. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Asteroptychius sancti-ludovici ST. JOHN & WORTHEN. 



Asteroptychius sancti-ludovici St. John & Worthen, 1875: Geol. Sur. Illi- 

 nois, vol. VI, p. 437, pi. xvi, figs. 3a-e. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone: St. Louis. 



Geisacanthus stellatus ST. JOHN & WORTHEN. 



Oeisacanthus stellatus St. John & Worthen, 1875 : Geol. Sur. Illinois, vol. 

 VI, p. 440, pi. xxi, figs. lOa-e. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone: Saint Louis. 



