Shiva Purana
त्रिकोणवृत्तं बाह्ये तु चतुरस्रात्मकं क्रमात् ॥ अभ्यर्च्योमिति साधारं स्थाप्य शंखं समर्चयेत् ॥ ५॥
The outer circle is triangular and consists of four rows in order. Placing the ordinary object, saying, “Abhyarchyomi,” one should worship the conchshell.
english translation
trikoNavRttaM bAhye tu caturasrAtmakaM kramAt ॥ abhyarcyomiti sAdhAraM sthApya zaMkhaM samarcayet ॥ 5॥
hk transliteration by Sanscript