A. M. Duggan-Cronin, “Bomvana Initiates,” South Africa, c. 1930.
From what I understand, ‘Bomvana’ is a Xhosa clan name.
Xhosa clan names are family names which are considered more important than surnames among Xhosa people.
Each Xhosa person can trace their family history back to a specific male ancestor or stock. Mentioning the clan name of someone you wish to thank is the highest form of respect, and it is considered polite to enquire after someone’s clan name when you meet them. The clan name is also sometimes used as an exclamation by members of that clan.
When a woman marries she may take her husband’s surname, but she always keeps her own clan name, adding the prefix Ma- to it. A man and a woman who have the same clan name may not marry, as they are considered to be related.