BULL. GEOL. SOC. AM. 



VOL. 11, 1899, PL. 45 



Figure 1. — Thomsonite of Type Ilia 

 Two-thirds natural size 



Figure 2.— Cavity lined with Chabazite and Thomsonite of Type I and of Type III 

 Mesolite needles continue growth of Thomsonite of Type III. Two-thirds natural size 



THOMSONITE OF TYPE Ilia AND MINERAL LINED CAVITY 



