Gabon, Cameroon and Equatorial Guinea
NGONTANG mask (all seeing mask)
Known as Ngontang (or Ngontanga), this mask variety appeared among the Fang people of southern
Cameroon and Gabon shortly before 1920. It represents a spirit of the dead visiting as a young white woman
from the world beyond. The mask was used to locate sorcerers–those who misuse spiritual powers–but also
performs at feasts, funerals, celebrations of birth, and on the occasion of an important communal decision.
Fang interpretation of the four faces on this mask varies from four spirits to four stages of life to four
relatives. It should be noted that examples exist with one, two, or three faces. Moreover, many examples bear
mask-like faces that are all of the same size.
Sources: A History of Art in Africa / Africa - The Art of a Continent / The Tribal Art of Africa
I do not have a Ngontang mask in my collection.
Information and examples below for reference purposes.
Images from the book    
African Masks from the Barbier-Mueller Collection
Map source: