ft . HAGA AND Prof. F. M. JAEGER: RONTGENPATTERNS OF TETRAGONAL CRYSTALS. PLATE IIL. 
Fig. 9. 
Potassiumd ihydrophosphate. Plate parallel to (110). 
Fig. 17. 
Penta-erythrite. Plate parallel to (001). 
Wulfenite. Plate parallel to (001). 
ngs 
of the Acad. of Sciences, Amsterdam XVIII Ao 1915/1916. HELIOTYPE, VAN LEER. AMSTERDAM. 
