Shiva Purana
तथैव देवगन्धर्वा यक्षाः किंपुरुषादयः ॥ वर्णास्तत्रैव चत्वारो निजानुष्ठानतत्पराः ॥ ४० ॥
Similarly the devas gandharvas yakshas kimpurushas and others There are four varnas devoted to their own rituals.
english translation
tathaiva devagandharvA yakSAH kiMpuruSAdayaH ॥ varNAstatraiva catvAro nijAnuSThAnatatparAH ॥ 40 ॥
hk transliteration by Sanscript