A chironema is an arm-shaped extension of one's soul. It is boneless and can become incredibly long. They interact with other souls and chironemata and may grab them with their sticky fingers. Chironemata are also hollow, and inside them, matter loses inertia.
They are invisible to most onlookers, but they can be seen through a hagalith. Some necromancers are also known to be able to see them.