PALACHE. — CRYSTALLOGRAPHY OF LEA Dili LL1TE. 463 



The combination shown in Figure 10 does not exactly correspond to 

 any of the measured crystals, although the forms present differ but 

 little from those observed on one crystal (Table IV, p. 456, no. 13), 

 which is, however, even more complex. It reproduces approximately 

 the more complex type of combination prevailing among the Nevada 

 crystals and illustrates the relations of most of the new forms. 



The amount of leadhillite present in Dr. Jaggar's specimens from 

 the Quartette Gold Mine was so small as to preclude the possibility 

 of obtaining sufficient material for chemical analysis or for physical 

 investigation. The hope that more material would be found suitable 

 for such studies has not, however, been fulfilled after the lapse of two 

 years or more. 



The table of angles (Table V), calculated according to Goldschmidt 

 (Winkeltabellen, 1897, p. 19 a) for the new axial ratio derived from the 

 Utah crystals and here adopted, includes all the observed forms of lead- 

 hillite, which are also shown in the gnomonic projection (Plate 3). 



