No. 2385. CRY ST ALLOGRAPH 1C STUDY OF DAT0LITE.—8HANN0N. 537 



Zone No. 17. — Negative pyramid zone. 



(010) : (302) : (010). Symbol j • y— J" 



Form... 



Symbol. 

 v-l .... 

 No 



This zone is entirely normal and is complete. 



Zone No. 18. — Diagonal zone. 

 (110) : (101) : (011) : (IlO). Symbol y 



b 

 010 



Form... 



Symbol. 

 Nt 



/ m 



\no 



9 

 312 



1/2 



This zone though incomplete is normal. 



Zone No. 19. — Diagonal zone. 

 (120) : (102) : (Oil) : (120). Symbol j 



Form... 

 Symbol . 



110 



120 



Dividing at and reversing the first part: 



2v. 



1/2 3/4 7/8 1 oo 

 1 3/2 7/4 2 oo 



Oil 2 oo 



This zone is normal with 2 forms missing, and 1 form, 768, which 

 is here listed as new, extra. The second part of the original zone is: 



5v . 

 N, 



Though incomplete this portion is normal. 



Zone No. 20a. — Positive vertical pyramid zone. 



k h l 

 (001) • (120). Symbol j- j, = ^» 



lorm |{ m 



Symbol. 

 Ni. 



4! 



This zone is normal with 4 forms missiinr. 



