E. S. Dana — Chondroditt from the lllly-FoKfer Iron Mine. 81 



without the foniiation of distinct planes, as is so common in many 

 species ; and then nothing of course couhl he done. 



The foUowing tables, VII, VIII, TX, X, include the measured 

 angles, with the symbols obtained, and the corresponding angles be- 

 longing to them, for a considerable number of these minute planes. 

 Those occurring on each individual crystal are arranged together, be- 

 ing expressed by the same letter, and where the crystal has been 

 figured, this is also indicated. Upwards of one-hundred of these 

 planes were measured, and an attempt was made in every case to ob- 

 tain a satisfactory index. It was concluded, however, to discard the 



Table VII. 



M 



Trans. Conn. Acad., Vol. III. 1 1 



.July, 1875. 



