SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 57, NUMBER 6 



CAMBRIAN 

 GEOLOGY AND PALEONTOLOGY 



II 



No. 6.-MIDDLH CAMBRIAN BRANCHIOPODA, 



MALACOSTRACA, TRILOBITA, AND 



MEROSTOMATA 



With Plates 24 to 34 



BY 

 CHARLES D. WALCOTT 



TUBLICATION 2051) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



MARCH 13, 1912 



