Smithsonian Report, 1 91 5.— Walcott. 



Plate 13. 



Cambrian Brachiopoda. 



a=area- c/"=cardinal muscle scar; F=foramen; F'=cast of foraminal tube; /(-central muscle 

 sear; •i=transmedian muscle scar; j=anterior lateral muscle scar; ■z's=vaseular smus. 



Obolus, Dicdlomus, LingulrUa, Acrothele, and other genera are represented from localities in the 

 'United States, Canada, Sweden, France, and China. 



