U. S. B. F.— Doc. 890. 



Plate VIII. 







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TOP, BORERS OR "DRILLS" (THAIS HAEMASTOMA) OF THE GULF COAST; 

 CENTER, SO-CALLED "RED GRASS," THE EGG CASES OF THE BORERS; 

 BOTTOM, OYSTER SPAT DRILLED BY BORERS. 



Natural size. (After Moore and Pope.) 



