NO. 3 CAMBRIAN TRILOBITES 247 



PAGE 



Crepiccphalus sp. undt ( i ) 218 



Fig. 4. (Natural size.) Dorsal view of a pygidium. U. S. National 

 Museum, Catalogue No. 61681. 



From Upper Cambrian: (107) Maryville limestone; 11 miles 

 (17.6 km.) northwest of Knoxville, Tennessee. 



4a. (Natural size.) Interior of a large pygidium. U. S. National 

 Museum, Catalogue No. 61682. 



From Upper Cambrian: (16) thin, slabby limestone of Cona- 

 sauga formation ; Murphrees Valley, Blount County, Alabama. 



