NO. 5 CAMBRIAN TRILOBITES 4I7 



Bathyuriscus adccus Walcott— Continued. page 



3f. (X2.) Thoracic segments. U. S. National ]\Iuseum, Cata- 

 logue No. 62634. 



The specimens represented hy figs. 3, ^a-c are from locality 58J, 

 Middle Cambrian: Stephen formation about 1,900 feet (579 m.) 

 above the Lower Cambrian and 3,100 feet (945 m.) below the Upper 

 Cambrian, near the base of the limestone forming 2 of the Stephen 

 formation, on the east side of Mount Stephen about 3,000 feet (914 

 m.) above the Canadian Pacific Railway track (north of the tunnel), 

 3 miles (4.8 km.) east of Field, British Columbia, Canada. 



Bathyuriscus ? bithus Walcott '. 340 



Fig. 4. (Natural size.) Cranidium somewhat crushed in the argil- 

 laceous shale. U. S. National Museum, Catalogue No. 

 62635. 

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

 Museum, Catalogue No. 62636. 



The specimens represented by figs. 4 and 4a are from locality 55c, 

 jMiddle Cambrian: Spence shale member of the Ute formation; 

 about 50 feet (i5-2 m.) above the Brigham quartzite, and 2,755 feet 

 (839.7 m.) below the Upper Cambrian, in a ravine running up into 

 Danish Flat from Mill Canyon, about 6 miles (9.6 km.) west-south- 

 west of Libertv and 15 miles (24.2 km.) west of Montpelier, Bear 

 Lake County, Idaho. 



