The affix ṇini comes in the sense of 'enounced by him' after the words śaunaka etc. in denoting chandas (Vedas).,
This debars छ and अण् ॥ Thus शौनकेन प्रोक्तंमधीयते = शौनकिनः 'who study 4.2.64 the Chhandas enounced by Saunaka.' वाजसनेयिनः &c.
Why do we say 'in denoting Chhandas'? Observe शौनकीया शिक्षा 'the orthography of Saunaka.'
The word कठशाठ occurs in this list. This must always be taken as a compound for affixing this affix. After the single word कठ the affix is elided 4.3.107. Thus कठशाठाभ्यां प्रोक्तामधीयते = काठशाठिनः ॥
1 शौनक, 2 वाजसनेय, 3 शार्ङ्गरव, 4 शापेय (सांपेय), 5 शाष्पेय (शाखेय) 6 खाडायन, 7 स्तम्भ (स्कम्भ), 8 स्कन्ध, 9 देवदर्शन, 10 रज्जुभार, 11 रज्जुकण्ठ, 12 कठशाठ, 13 कषाय (कशाय) 14 तल, 15 दण्ड, 16 पुरुषांसक (पुरुषासक), 17 अश्वपेज (अश्वपेठा), 18 साङ्गरव, 19 स्कन्द, 20 देवदत्तशठ, 21 तलवकार.,