Natyashastra
षष्ठतालस्तथा ज्ञेयो निष्क्रामस्तर्जनीकृतः । शम्याष्टमी ततस्तालो नवमी तु कला स्मृता ॥ ४८॥
The sixth beat is to be known as the one where the index finger is moved out; The eighth is marked by a strike of the staff, and the ninth is considered a fractional beat (kalā).
english translation
SaSThatAlastathA jJeyo niSkrAmastarjanIkRtaH । zamyASTamI tatastAlo navamI tu kalA smRtA ॥ 48॥
hk transliteration by Sanscript