46 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
MANGANESE AT MANGO AND THITHIA. 
At Mango a great deposit of manganese occurs at a low level (about 
100 feet above high-water mark). The earth is decidedly black for a 
great distance from the surface, being as much as 30 feet thick in 
places. Large pieces of manganese lie about the ground as scattered 
blocks. 
At Thithia smaller pieces occur. One I picked up was a sphere | inch 
in diameter. 
At Naitamba the blocks are of irregular shape, as at Mango. 
