The affix cha comes in the sense of 'this is his' after the words raivatika etc.,
All these words end with Gotra affixes, and require वुञ् 4.3.126, is ordains छ instead. Thus रैवतिकीयः, स्वापिशीयः &c.
1 रैवतिक, 2 स्वापिशि, 3 क्षैमवृद्धि, 4 गौरग्रीवि (गौरग्रीव), 5 औदमेघि (औदमेयि), 6 औदवापि (औदवाहि) 7 बैजवापि.,