CRUSTACEANS. 239 



Surface smootli, or sometimes showing faint traces of minute 

 granules or small, scattering pits. 



Horizon and looalUi.es — Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Leperditia sublaevis ( Shumard ). 



Cythe?-e sublcevis Shumard, 1855: Geol. Sur. Missouri, Ann. Rep., p 195. 



pi. B, tig. 16. 

 Leperditia iublceuis Vogdes, 1890: U. S. Geol. Sur. , Bui. 63, p, 172. 



" Carapace small, subovate, smooth, nearly as long again as 

 high, moderately convex, most prominent posteriorly; pos- 

 terior end a little wider than the anterior, rounded; ventral 

 margin straight, its anterior extremity extended into a minute 

 pointed process. Just within the borders a faintly impressed 

 line may be traced entirely around the valves. Surface highly 

 polished." (Shumard.) 



Horizon and localities. — Silurian, First Magnesian lime- 

 stone : Hamilton creek ( St. Louis county ), Ste. Genevieve 

 county, Spencer creek (Ralls county). 



Solenocaris sancti-ludovici Worthen. 



Solenocaris sancti-ludovid Worthen, 1884: Illinois State. Mus. Nat. Hist., 



Bui. 2, p. 4. 

 Solenocaris sancti-ludovici Worthen, 1891 : Geol. Sur. Illinois, vol. VIII, p. 



153, pi. xxviii, fig. 3. 



Carapace narrow, much elongated, being three times as 

 long as high, slightly convex ; dorsal and ventral margins 

 nearly straight. 



Horizon and localities. — Lower Carboniferous, Saint Louis 

 limestone: Saint Louis. 



Colpocarls chesterensis Worthen. 



Colpocaris chesterensis Worthen, 1884: Illinois State Mus. Nat. Hist., 



Bui. 2, p. 3. 

 Colpocaris chesterensis Worthen, 1891 : Geol. Sur. Illinois, vol. VIII, p. 



153, pi. xxviii, fig. 2 



Carapace large, subovate, twice as long as high, with regu- 

 larly curving margins. 



Horizon and localities. — Lower Carboniferous, Kaskaskia 

 limestone: Chester (Illinois). 



