326 SMITHSOXIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 54 



PAGE 



Holiiiia ? niacer Walcott 313 



Fig. I. (X 3-) Type specimen of the species. (From locality i2v.) 

 Lower Cambrian shale, Fruitville, Lancaster County, Penn- 

 sylvania. U. S. National Museum, Catalogue No. 60092. 



Olenellus truemani Walcott 316 



Fig. 2. (X 2.) Surface of shale with two compressed, nearly entire 

 dorsal shields and a small cephalon. (Locality 6ik.) \J. S. 

 National Museum, Catalogue No. 60084. 

 3. (X 2.) Compressed and slightly distorted hypostoma. (Local- 

 ity 6ik.) U. S. National Museum, Catalogue No. 60085. 

 4 and 5. (X S-) Two small hypostomas. (Locality 6ik.) U. S. 

 National Museum, Catalogue No. 60086. 



6. (Natural size.) Cephalon with outer test of cheeks exfoliated 



so as to show casts of radial canals. (Locality 6ik.) U. S. 

 National Museum, Catalogue No. 60087. 



7. (Natural size.) Broad, flattened dorsal shield with enlarged 



third thoracic segment. (Locality 61k.) LT. S. National 

 Museum, Catalogue No. 60088. 



8. (X 2.) A small, almost entire dorsal shield. (Locality 6ik.) 



U. S. National Museum, Catalogue No. 60089. 

 g. (X 2.) A small cephalon preserving much of its original con- 

 vexity. The attached thoracic segments are more or less 

 displaced. (Locality 6ik.) U. S. National Museum, Cata- 

 logue No. 60090. 

 10. (X 2.) Small, nearly entire, undistorted dorsal shield with 

 large third thoracic segment. (Locality 6ik.) U. S. 

 National Museum, Catalogue No. 6oogi. 

 The specimens represented by figs. 2-10 are from locality 6ik. 

 Lower Cambrian: Mahto formation; dark, hard siliceous shale, 

 northeast base of Mumm Peak above Mural Glacier on the west side 

 of Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit of 

 Robson Peak and northwest of Yellowhead Pass, in western All^erta, 

 Canada. 



