THE NATURAL HISTORY SURVEY. 2OQ 



1887. Proetus determinalus. Foerste, Bull. Sci. Lab. Den. Univ., 

 vol. 2, p. 91, pi. 8, figs. 2, 3, 3a. 



Clinton: Near Dayton, Ohio. 



1895. Proetus determinatus. Foerste, Geol. Surv. Ohio, vol. 7, 

 p. 523, pi. 26, fig. 5, pi. 27, figs. 2, 3, 3a. 



Clinton: Ohio. 

 Proetus? handwerki Weller. 



1907. Proetus ? handwerki. Weller, This Bulletin, p. 229, pi. 20, 

 figs. 8-9. 



Niagaran: Near Lemont, 111. 

 Proetus pachydermatus Barrett. 



1878. Proetus pachydermatus. Barrett, Am. Jour. Sci., 3rd ser., 

 vol. 15, p. 371. 



Coralline limestone. Nearpass Cliff, N. J. 



1903. Proetus pachydermatus. Weller, Pal. N. J., vol. 3, p. 248, 

 pi. 22. figs. 16-21. . 



Decker Ferry: Nearpass Quarry, N. J. 

 Proetus spinosa Weller. 



1903. Proetus ? spinosa. Weller, Pal. N. J., vol. 3, p. 250, pi. 22. 

 fig. 26. 



Decker Ferry: Nearpass Quarry, N. J. 

 Proetus stokesii Hall. 



1852. Proetus stokesii. Hall, Pal. N. Y., vol. 2, p. 316, pi. 67, 

 figs. 13-14. 



Niagara: Lockport, N. Y. 

 Proetus subannulatus van Ing. 



1901. Proetus subannulatus.. van Ing., School of Mines Quart., 

 N vol. 23, p. 57, fig. 18, p. 54. 



Silurian: St. Clair Spring, Independence Co., Ark. 



SPHAEREXOCHUS Beyr., 1845. 



Sphaerexochus mirus (various authors), see Sphaerexochus romingeri 



Hall. 



Sphaerexochus pisum Foerste, see Deiphon forbesi Barr. 

 Sphaerexochus romingeri f Hall. 



1860. Sphaerexochus mirus. Roemer, Sil. Faun. West. Tenn,, p. 

 81, pi. 5, fig. 20. 



Silurian: Tennessee. 



1867. Sphaerexochus romingeri. Hall, Geol. Surv. Wis., vol. 1, 

 p. 434 (no description). 



Niagara: Milwaukee and Waukesha, Wis. 



1865. Sphaerexochus mirus. Hall, Adv. Sheets, 18th Rep. N. Y. 

 St. Cab. Nat. Hist., p. 30. 



Niagara: Milwaukee, Racine, Waukesha and Green- 

 field, Wis.; Bridgeport, 111. , 



1867. Sphaerexochus mirus. Hall. 20th Rep. N. Y. St. Cab. Nat. 

 Hist., p. 334. 



Niagara: Milwaukee, Racine, Waukesha and Green- 

 field, Wis. ; Bridgeport, 111. 



