146 



TRAVIS— PYRITE FROM CORNWALL. 



[June 22 



There is considerable discrepancy here, (474) in particular being 

 half a degree out. This is very probably due to the inaccuracy of 

 the method by which it was measured. It is much more probable 

 that the faces have the symbol given than that they are diploids with 

 complex, ratios approaching these symbols, for two other trisocta- 

 hedrons have been observed, (221) and (774), and one other tra- 

 pezohedron (211), while no diploids were observed except in the 

 zone of (ill, 210). 



It will be noticed that one form given by Blake, namely (432), 

 was not observed, — a form with simple ratio, and one which if it 

 occurred at all would be more common than forms of more complex 

 ratios, as (i 5.1 1.7) and (i 1.8.5) There is some doubt in the 

 writer's mind as to whether the (432) of Blake really is (432) or is 

 a diploid with more complex ratio, as the above. 



The following table sets forth the forms observed on each crystal. 



Crystal 23 is perhaps the only one of this series worthy of a 

 separate description. This crystal is about 1.8 cm. in diameter. It 



