1. Species Nyassia acutalis Bourguignat, 1889 accepted as Melanoides polymorpha (E. A. Smith, 1878) (junior synonym)
2. Species Nyassia hermosa Bourguignat, 1889 accepted as Melanoides polymorpha (E. A. Smith, 1878) (junior synonym)
3. Species Nyassia lacustris Bourguignat, 1889 accepted as Melanoides polymorpha (E. A. Smith, 1878) (junior synonym)
4. Species Nyassia magnifica Bourguignat, 1889 accepted as Melanoides magnifica (Bourguignat, 1889) (original combination)
5. Species Nyassia nodulosa Bourguignat, 1889 accepted as Melanoides polymorpha (E. A. Smith, 1878) (junior synonym)
6. Species Nyassia rivularis Bourguignat, 1889 accepted as Melanoides polymorpha (E. A. Smith, 1878) (junior synonym)
7. Species Nyassia callista Bourguignat, 1889 (uncertain, use in recent literature not established by editor)
8. Species Nyassia elegans Bourguignat, 1889 (uncertain, use in recent literature not established by editor)
9. Species Nyassia giraudi Bourguignat, 1889 (uncertain, use in recent literature not established by editor)
10. Species Nyassia idia Bourguignat, 1889 (uncertain, use in recent literature not established by editor)
11. Species Nyassia paradoxa Bourguignat, 1889 (uncertain, use in recent literature not established by editor)
12. Species Nyassia thaumasta Bourguignat, 1889 (uncertain, use in recent literature not established by editor)

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