BULL. GEOL. SOC. AM. 



VOL. 11, 1899, PL. 44 



Figure 1. — Thomsonite of Type Ha 

 Underlain by Thomsonite of Typo I. One-half natural size 



Figure 2. — Thomsonite of Type III 

 < ►ne-half natural size 



THOMSONITE OF TYPES lla AND III 



