The shell covering a seed is sometimes called a hull.
Seed coat.
the valence shell
germination
linseed.
Burr
seed leaves
To effectively shell sunflower seeds, first crack the shell with your teeth or a nutcracker. Then, use your fingers to remove the seed from the shell. Repeat the process for each seed.
gladius
Orbital x ray
Aril, testa, hull
An egg
To effectively deshell sunflower seeds, you can crack the shell with your teeth or use your fingernails to split the shell open. Another method is to use a nutcracker or a pair of pliers to crack the shell. Once cracked, you can easily remove the seed from the shell.