BULL. GEOL. SOC. AM. 



VOL. 24, 1912. PL. 31 



Figure 1. — A Detail of the weathered Surface of the Bighorn Dolomite 

 Showing a branching alga (?» weathered out in relief. Darby Creek in the Teton Range 



Figure 2. — A branching Welt suggesting algal Origin 

 Teton Canyon, Teton Range 



BIGHORN DOLOMITE 



