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 

 <;reat 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 1 inch 

 in diameter. 



At Naitamba the blocks are of irregular shape, as at Mango. 



