54 CARBONIFEROUS AMMONOIDS OF AMERICA. 



This species differs (according to Winchell) from 1'. lyonl in the greater 

 relative length of the second lateral lobe and the auxiliary saddle, and also 

 in the greater compression of the cross section of the whorl; from 1'. hcnsJowi 

 Sowerby in the more acute lateral lobes and greater length of the saddles. 



Occurrence. — Lower Carboniferous, Kinderhook stage, Marshall, Mich. 



Pkolecakites ? LOuisiANENSis Kowle3^ 



PI. VI, figs. G-S. 



1895. Goniatitt's lou!slaii<'ri)<if<, R. R. Rowley. Am. Geologist, Vol. XVI. p. 321, 

 PI. XXXI, figs. 1.5-lS. 



This minute species is of somewhat doubtful systematic position. It 

 is hardly possible to determine it from Rowley's figures, but the Avriter is 

 indebted to Dr. Stuart Weller, of the University of Chicago, for the loan 

 of several well-preserved specimens from the Gin-ley collection. On these 

 the lanceolate type of lobes can be clearly seen, resembling the young 

 stages of Pronorites cydolohus, the so-called '' Ibergiceras" stage. 



The whorls are evolute, depressed, little embi-acing. The shell lias 

 one or two constrictions to a revolution. The general shape reminds one 

 strongly of Anarcestes, but the septa show that the transition to the stock 

 of the Prolecanitida' has already been made. The ventral lobe is long, 

 tongue-shaped, and undivided; the lateral lobe is lanceolate, and the 

 second lateral or auxiliary lobe is shallow, broad, and lies just outside of 

 the umbilicus. The internal septa consist of a pointed antisiphonal lobe, 

 flanked by a ]3air of shallow laterals. All the saddles are rounded. 



Occurrence. — Lower Carboniferous, Kinderhook stage. Louisiana, Mo. 



The figured specimen is deposited in the paleontologic collection. 

 Walker Museum, University of Chicago (Gurley collection). 



Prolecanites lyoni Meek and Wortheu. 

 PI. XVI, fig. 18; PL XIX, figs. D-ll. 



1S60. Goniatites lyonl, Meek and Worthen. Proc. Acad. Nat. Sci. Phila., iMtJO, p. 471. 

 1860. Goniatitea hyas, J. Hall, Thirteenth Rept. N. Y. State Cab. Nat. Hist., p. 103, 



figs. 17,' 18. 

 1866. Gonixdites lyoni, Meek and Worthen, Geol. Surv. Illinois, Vol. 11, j). 165, 



PI. XIV, figs, lla-c. 



