It will evolve if you use a water stone on it.
Shellder does not evolve by level. Use a water stone on it (bought from celadon department store) when you are ready to evolve it
it evolve at level 40
On level 28!!!!
You have to trade it
Level 55.
Level 40.
Level 23.
level 16
Paras should evolve in Parasect at level 24.
It does not evolve at a certain level. It evolves when you use a Fire Stone on it.
Only when you use a fire stone on growlithe it will evolve.
It evolves at level 28.