232 VERTEBRATES. 



Polyrhizodus williamsi St. JOHN & WORTHEN. 



Polyrhizodus williamn St, John & Worthei, 1875 : G-eol. Sur. Illinois, vol. 

 VI, p. 384, pi. x A, tigs. 23a-b. 



Horizon and localities. Lower Carboniferous, Keokuk 

 limestone : Boonville. 



Polyrhizodus littoni NEWBERRY & WORTHEN. 



Polyrhizodus littoni Newberry & Worthen 1870: Geol. Sur. Illinois, vol. IV, 

 p. 596, pi. iii, figs. 16-16a. 



Horizon and localities. ~Lower Carboniferous, Saint Louis 

 limestone: Saint Louis. 



Polyrhizodus am pi us ST. JOHN & WORTHEN. 



Polyrhizodus amplus St. John & Worthen, 1875: Geol. Sur. Illinois, vol. 

 VI, p, 387, pi. xiii, figs. 13a-c. 



Horizon and localities Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Petalorhynchus distortus ST. JOHN & WORTHEN. 



Petalorhynchus distortus St. John & Worthen, 1875: Geol. Sur, Illinois, 

 vol. VI, p. 406, pi. xii, figs. 7a-c. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Petalorhynchus pseudosagittatus ST. JOHN & WORTHEN. 

 Petalorhynchus pseudosagittatus St . John & Worthen, 1875: Geol. Sur. Illi- 

 nois, vol. VI, p. 405, pi. xii, figs. la-c. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Peltodus quadratus ST. JOHN & WORTHEX. 



Peltodus quadratus St. John & Worthen, 1875: Geol. Sur. Illinois, vol. VI, 

 p. 410, pi. xiii, figs. 6a-b. 



Horizon and localities. Lower Carboniferous, Saint Louis 

 limestone : Saint Louis. 



Psephodus latus ST. JOHN& WORTHEN. 



Psephodas latus St.- John & Worthen, 1883: Geol. Sur. Illinois, vol. VIE, 

 p. 72, pi. ii, figs. la-d. 



Horizon and localities. Lower Carboniferous, Saint Louis- 

 limestone : Saint Louis. 



