Priyavrata-vaṃśa and Saptadvīpa Vibhāga (प्रियव्रतवंशः सप्तद्वीपविभागश्च)
शिवस्तु पेचमस्तेषां क्षेमकः षष्ठ उच्यते / ध्रुवस्तु सप्तमो ज्ञेयः पुत्रा मेधातिथेः स्मृताः
śivastu pecamasteṣāṃ kṣemakaḥ ṣaṣṭha ucyate / dhruvastu saptamo jñeyaḥ putrā medhātitheḥ smṛtāḥ
Of them, the fifth was Śiva, and the sixth is called Kṣemaka. The seventh should be known as Dhruva—these are remembered as the sons of Medhātithi.