Figure 6-8. Salem limestone, St. Genevieve, Missouri. Acetic acid etch. Surface rough; 

 notable differential etching; clastic character of limestone well shown; fossil fragments 

 project notably above ground mass; crinoid stem fragments at bottom of specimen show 

 differential solution; in upper center is a spine, possibly of an echinoid; presence of 

 impurities not well shown. X18 (Lamar) 



