Wooden slit drum, possibly a gugu, Zande culture. The instrument is carved in the shape of a stylised cow.
This instrument was probably collected by Archibald Norman Tucker (1904-1980), author of 'Tribal music and dancing in the Southern Sudan at social and ceremonial gatherings' (1933) and 'The non-Bantu languages of North-Eastern Africa: with a supplement on the non-Bantu languages of Southern Africa' (1956)