PLATE XLIX 161 
Oso.us (WESTONIA) WAsATCHENSIS Walcott (p. 466). 
[Text figs. 41A-F, p. 467.] 
Ficure 5. Compressed and crushed ventral valve. U.S. Nat. Mus. Cat. No. 57098a. 
5a. Dorsal valve flattened in the siliceous shale. U.S. Nat. Mus. Cat. No. 57098b. 
The specimens represented are both from Locality 32x, Middle Oambrian shale in Wasatch Canyon, Boxelder 
County, Utah. 
Oxso.tus (WESTONIA) ELLA ONAQUIENSIS Walcott (p. 459). 
Ficure 6. Compressed, exfoliated dorsal valve, the type specimen. U.S. Nat. Mus. Cat. No. 51716a. 
6a. Enlargement of the surface of another specimen to show the zigzag, transverse strie. U.S. Nat. Mus. 
Cat. No. 51716b. 
The specimens represented are both from Locality 33f, Middle Cambrian shales, Onaqui Range, Tooele County, 
Utah. 
62667°—vo1 51, pr 2—12 iat 
