Agniveshyagrihyasutra 3.6.2.14

3.6.2.14

atha yadi dagdhaḥ syādasthīnyāhṛtyāntarvedi śarīrāṇāṃ kṛṣṇājine puruṣākṛtiṃ kṛtvā teṣūpari pātrāṇi citvā kuśataruṇakaiḥ praticchādya prasiddhamupoṣeyuḥ \

Now, if he should be burned, having brought the bones, having made the shape of a man out of the bones on a black antelope skin inside the altar, having piled the sacrificial vessels on top of them, and having covered them with young kuśa shoots, they should burn him in the established manner.