A name given to a part of the river which flows from the east of Anotatta, before it ultimately divides into the five great rivers, Gangā, Yamunā, etc.
The Ummagga-Gangā is the continuation of the Bahala-Gangā and flows for sixty leagues under the earth, till it reaches the rock named Vijjha. SnA.ii.439; AA.ii.760; UdA.302.