Shiva Purana
कोष्ठानि स्युस्ततस्तस्य मध्यकोष्ठं तु कर्णिका॥ कोष्ठाष्टकं बहिस्तस्य दलाष्टकमिहोच्यते॥ ६॥
Then there should be cells and the middle cell should be the ear. The eight cells outside it are called the eight petals here.
english translation
koSThAni syustatastasya madhyakoSThaM tu karNikA॥ koSThASTakaM bahistasya dalASTakamihocyate॥ 6॥
hk transliteration by Sanscript