Complex sentence: These were at first described as inhabitants of the Nile system (Aethiopia): later traditions confined to their habitat to a particular island in the Brisone River, or even shifted it to India.
Split into simpler sentences: These were at first described as inhabitants of the Nile system (Aethiopia). Later traditions confined to their habitat to a particular island in the Brisone River, or shifted it to India.