NO. 5 CAMBRIAN TRILOBITES 4I9 



Bathyuriscns {Poliella} sylla Walcott — Continued. page 



3 J. (X3-) Pygidium. U. S. National Museum, Catalogue No. 



62649. 

 3c. (X3-) A small cranidium showing glabellar furrows. U. S. 



National Museum, Catalogue No. 62650. 

 3/- (X3-) Hypostoma with ears restored in outline. U. S. National 



Museum, Catalogue No. 62651. 



The specimens represented by figs. 3, ^a-f are from locality 61 o, 

 Middle Cambrian : Chetang formation ; gray shaly limestone in 

 massive beds ; on northeast slope of Chetang Cliffs above Coleman 

 Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from 

 summit of Robson Peak, northwest of Yellowhead Pass, western 

 Alberta, Canada. 



Bathyuriscns batis Walcott 337 



Fig. 4. (Natural size.) Natural casts of distorted and compressed 

 specimens in a fine quartzitic sandstone. U. S. National 

 Museum, Catalogue No. 62652. 

 4a. (Natural size.) Dorsal shield, broadened by flattening in ma- 

 trix. U. S. National Museum, Catalogue No. 62653. 



The specimens represented by figs. 4 and 4a are from locality 59p, 

 Lower Cambrian: Millers Mountain, 10 miles (16 km.) north of 

 Columbus and west of Belleville, Esmeralda County, Nevada. 



