Plate XXIII. 
1907. 
Mac. 
GEOL. 
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eae esi. tee tiie 
pron 
oes 
Fc 
4] 
Figs. 1, 2.— Photographic Reproductions of thin slices of ice 0.3 inch in thickness. 
Figs. 3, 4.—Reproductions of surface-markings on glacier ice in cayes. 
