Nervous system- ariolimax
Typically, most people would say that slugs are very underdeveloped and un-evolved. As a matter of fact, on the evolutionary scale, Ariolimax is very similar to our own nervous system. Banana slugs have highly developed sensory organs- these send nerve impulses on clusters of neurons throughout its body. This process is basically the same as what happens in our own bodies when affected by an exterior stimuli. The central ganglia in these slugs function as a primitive brain. Information taken from the brain is relayed through nerve impulses to the slug's muscles and receptors. The sole nerve cord which runs down the length of the slug's body also allows changes in mental behavior, as opposed to simply reacting to physical stimuli. Again, this is highly similar to the functions which we undertake.