E 
o 
co 
V> 
</) 
03 
"U 
CO 
• mm 
<Si 
c 
03 
ZJ 
0) 
u. 
H— CO 
O 5 
0) « 
|.E 
CO CO 
</) 
L. 
CO 
0) 4_ 
SZ o 
" H- 
03 3 
CO 
■ MM 
0) 
I- 
■ 
*fr 
CNI 
e 
D 
O) 
NOTE: (A) Scanning electron micrograph of vertical fracture surface showing 
gradation of nacreous tablets into fine-grained structures at top and gradation 
of prisms into nacre at bottom x2000. The most recently deposited crystals 
are at the bottom of the micrograph. (B) Acetate peel showing similar grada¬ 
tions of nacre into fine-grained structures and prisms into nacre x125. Again, 
the most recently deposited crystals are at the bottom of the micrograph. 
171 
