NO. 3 CAMBRIAN TRILOBITES 239 



PAGE 



Millardia optata (Hall) 165 



Figs. 4, 4a, 4b. (X4-) Top, side, and front view of a small entire 



cranidium. U. S. National Museum, Catalogue No. 61626. 



4c. (X2.) Free cheek associated with the specimen represented 



by fig. 4. U. S. National Museum, Catalogue No. 61627. 



4d, 46, 4/. (X4-) Top, side, and front views of a small entire 



cranidium. U. S. National Museum, Catalogue No. 61628. 



The specimens represented by figs. 4, 4a-/ are from locality 79c, 



Eau Claire formation, near Hudson, St. Croix County, Wisconsin. 



Millardia avitas Walcott 165 



Figs. 5, 50, 56. (X 4-) Top view of type specimen of cranidium, with 

 outline of front and side views. U. S. National Museum, 

 Catalogue No. 61629. 

 5t-. (Natural size.) This is the same specimen as that represented 

 by fig. 5- 

 The specimen represented by figs. 5, 5a-c is from locality 107k, 

 Upper Cambrian : Butifalo Run limestone, 2 miles north of Benore 

 Post Office, Center County, Pennsylvania. 



