Manasara 12.93

12.93

maṇḍūkaṃ pāñcajanyaṃ ca matsyaṃ kūrmaṃ ca rājatam
indrādiṣu caturdikṣu vinyasettu yathākramam

a frog, a conch, a fish, and a tortoise made of silver, / one should place in due order in the four directions beginning with the east;