228 



Allen, Crenshaw, Johnston, and Larsen — 



Table X. — Summary of Crystal 





a 





i o 





<0 -i-i 







- 



e +- 1 Si 



-»J 



O Ph 



OB 





>i 



o 





& 



A 



1 



B 



1 



C 



I 



D 



9 



E 



2 



F 



2 



G 



2 



H 



2 



I 



3 



J 



3 



K 



3 



L 



3 



M 



3 



N 



3 







4 



P 



4 



Q 



4 



R 



4 



S 



4 



T 



4 



U 



4 



Faces represented 



(001 

 (001 

 (001 

 (001 

 (011 

 (001 

 (001 

 (001 

 (001 



(111 



(001 

 (001 

 (001 

 (001 

 (001 

 (001 

 (001 

 (011 

 (001 

 (001 

 (071 

 (001 



(111 



(001 



(111 



(001 

 (011 

 (001 

 (011) 



010 

 010 

 010 

 010 

 023 

 010 

 010 

 010 

 010 

 011 

 010 

 010 

 010 

 010 

 010 

 010 

 010 

 112 

 010 

 010 



010 



o-i- 



010 

 011 



010 



(110) (112) 



(110) 



(110) 



(110) (100) 



(110) 



(111) (221) 

 (110) (992) 



(110) (021) 

 (112) 

 (111) 



(111) (091) 

 (111) 

 (111) 

 (111) 



(021) (111) 

 (021) (lll)|59 c 



6(r± 

 59° 32' 



59° 50' 

 60° 10' 



59° 57' 

 60° ± 

 59 o / 



60° ± 



60° 

 59° 

 60° 

 59° 

 60° 

 59° 



22' ± 

 56' 



5' 

 36' 



4' 

 59' 

 53' 



at > 

 -^ co co 



CD 



<1 ftti 



66° 30' 0-9834 



65° 35' 0-9850 



65° 7' 0-9578 



65° 27' 0-9639 



° 59' 0-9376 

 ° 5' 0-9388 

 ° 57' 0-9732 



(021) (111)160° ± 

 (021) (111);60°± 



(110) (021)!60° + 

 20) 

 (110) (021) 59° 44' 



(021) (111)60° + 



010) (021) (111) 

 1.1.34) 



60° 30' + 



65° 30' 0-9648 



65°± 



66° 10' 0-9772 



62° 50' 0-9160 



64° 40' 0-9495 



■3.S 



co > 

 eg ^ 



-P £0rH 

 CD T3 C"* 



m2 s 



Pc 



55° 18' 0-9545 



55° 30' 0-9503 



62° 44' 



63° 15' 



62° 31' 



62° 14' 

 62° 19' 



62° 26' 



62° 18' 

 61° 38' 

 62° 8' 



the development of different faces in the zone (0 k I) from 

 those in the zone (A h I) strongly indicate orthorhombic sym- 

 metry. The crystals of the third preparation were, with few 

 exceptions, developed as is the crystal shown in fig. 18. The 

 development of the zonal and vicinal faces is shown in Hg. 19, 

 which is a stereographic projection of crystal I. The other 

 crystals of this lot are much like this, although the striations 

 of the zone (0 Jc l) are not usually so prominent. The crystals 



