NO. 3 CAMBRIAN TRILOBITES 237 



PAGE 



Norwoodia simplex Walcott 171 



Fig. 3. (X4-) An entire, slightly weathered specimen of the dorsal 

 shield. U. S. National Museum, Catalogue No. 61609. 

 :^a. (X 6.) Interior of a compressed dorsal shield. U. S. National 



Museum, Catalogue No. 61610. 

 3&. (X6.) An imperfect, small cranidium preserving something 

 of its original convexity. U. S. National Museum, Cata- 

 logue No. 61611. 



All the specimens illustrated are from localities 90a and 91, 

 Upper Cambrian : Conasauga shale ; at Cedar Bluff, Coosa River, 

 Cherokee County, Alabama. 



