Ficure 6-7. Salem limestone, St. Genevieve, Missouri. Hydrochloric acid etch. Surface 

 essentially plane; a clastic rock composed of oolite grains and fossil detrites; dark areas 

 are clear calcite; large fragment of crinoid stem in center of specimen; a few small 

 grains and masses of silica project above ground mass. X18 (Lamar) 



