Jellies consume prey with long “oral arms”, which are frilly projections extending form the mouth.
These arms are covered with stinging cells and wrap around and engulf food. This is a close up of one of these arms, gliding over a piece of glass. This arm is about 10 cm long.
Below is an extra close up. We’re looking at about 1cm of area. The opaque dots and bumps are bundles of stingers, each one on its own cell. You can actually see individual cells contracting.The long tube-like structure visible in the middle of the arm is where the two halves fold together, and where food is transported to the stomach.
These videos are of a species called Pelagia noctiluca, and were taken by me with animals I have raised in the lab.