196 



University of California. 



[Vol. 3. 







Symbol. 





Measured. 





Calculated. 





No. 



O 











































0) 



Odt. 



Miller. 



<f> 



(■ 





9 



P 





1 









001 



89 



5 59' 



14° 



14' 



90° 00' 



14° 



16' 



2 



]) 



0°o 



010 







00 



90 



00 



00 



90 



00 



3 



Yft 



OD 



no 



41 



06 







41 06 







4 



I 



oo2 



120 



24 



11 







23 34 











W 



+io 



103 



89 



59 



35 





90 00 



35 





6 



d 



+10 



102 



90 



15 



42 



27 





42 



50 



7 



k 



+ 10 



203 



t 





48 



44 





49 



02 



8 



V 



+ 10 



101 



89 



49 



58 



90 



i ( 



58 



00 



9 



X 



+ ii0 



302 



90 



15 



66 



18 



i t 



66 



15 



10 



9 



+20 



201 







71 



28 



i i 



71 



22 



11 





+J0 



904 







73 



00 





73 



03 



12 







01 . 



011 



9 



22 



57 



18 



9 21 



57 



24 



13 





— 12 



121 



19 



43 



73 



26 



19 29 



73 



00 



For the two forms r ~ Sill I and B = [ 332 J , in the zone 

 c m, the following interfacial angles were measured and calcu- 

 lated : 



Measured. Calculated. 

 c:r = (001) : (111) = 55° 55' 55° 59' 



c:B = (001) : (332) = 63° 13' 63° 13' 



Of the seven new forms, five were positive orthodomes, occur- 

 ring' on one crystal. Each form gave a distinct signal so that 

 the faces did not insensibly grade into one another. 



/ : = co 2 = \ 120}. This new prism was present on two crystals 

 as a fairly large form. The reflections, in both cases, 

 were but fair. 



d = +10 — 1 102} . This dome was relatively a large face, about 

 equal in size to w = \ 108 ( . The i*eflection was fair. 



k = -f-fO = { 203}. This form was not quite as broad as the 

 preceding dome. 



x =.+f0 = S302|. Two occurrences of this dome were noted, 

 on crystal No. 5, as a very narrow face, and on crystal 

 No. 8, as a broader face. 



q = +20 = |201( . This form was a very narrow dome. 



j= +f0 = 1904 1. This dome was also very narrow. The 

 crystal on which these domes occurred was somewhat 



