Others belonging to this group are the digging and earth-working castes, the Beldars, Murhas, Nunias and so on, practically all derived from the indigenous tribes, who wander about seeking employment from the cultivators in the construction and repair of field embankments and excavation of wells and tanks; and various fishing and boating castes, as the Injhwars, Naodas, Murhas and Kewats, who rank as equal to the Dhimars, though they may not be employed in household or village service.

Such castes, almost entirely derived from the non-Aryan tribes, may have come gradually into existence as the wants of society developed and new functions were specialised; they would naturally be given the social status already attaching to the village menial castes.
34.

The non-Aryan tribes.
The fourth group in the scheme of precedence comprises the non-Aryan or indigenous tribes, who are really outside the caste system when this is considered as the social organisation of the Hindus, so long at least as they continue to worship their own tribal deities, and show no respect for Brahmans nor for the cow.

These tribes have, however, entered the Hindu polity in various positions.

The leaders of some of them who were dominant in the early period were admitted to the Kshatriya or Rajput caste, and the origin of a few of the Rajput clans can be traced to the old Bhar and other tribes.