The affix ṣpha is invariably added in the feminine after the words beginning with lohita and ending with kta when they take the affix yañ,
The words लोहित &c. are a subdivision of Gargadi class ( IV. 1. 105). The present sutra makes the application of the affix ष्फ, compulsory while it was optional in the last. The word कत refers to the independent pratipadika कत in the said subdivision, which follows immediately after the word कपि, and not to the word कुरुकत of the same class, where the word कत is not an independent full nominal-stem but a member only. Thus, लोहित्यायनी, शांशित्यायनी, बाभ्रव्यायणी ॥
Karika कण्वात्तु शकलः पूर्वः कतादुत्तर इष्यते ॥
पूर्वोत्तरौ तदन्तादी ष्फाणौ तत्र प्रयोजनम् ॥
For the purposes of the application of ष्फ and अण्, the word शकल which is enumerated in the Ganapatha after the word कण्व (See 4.1.105) should be regarded as if it stood immediately before कण्व and after कत ॥ Thus we have शाकल्यायनी (with ष्फ), and शकलाः with अण्, meaning शाकल्यस्येमे छात्राः 'the pupils of Sakalya'.,