Background Information
Snails are the most numerous mollusks out there comprising of 80% of Mollusca. Because mollusks are a large group of invertebrate animals, they normally have very soft bodies. Mollusks also do not have legs, and as you've read so far, the closest thing the Giant Squid has to legs is their tentacles. Snails are a part of the three main groups of mollusks, while oysters and clams, and squids and octopuses are the other two main groups. That doesn't mean, however, that their aren't any other groups. The Snail has a spiral shell that is all completely together, and they are probably the most diverse group of mollusks. Only a few snail groups have stopped growing spiraled shells. These groups are commonly known as slugs.
Nervous System
The nervous system of the snail is very different from the nervous system of the Giant Squid. The snail actually has no brain at all. For a nervous system to replace this lost brain, however, the cell bodies of nerve cells are concentrated in ganglia for and in important parts of the body. The nervous system of snails is very similar to the nervous system of worms, also. Both the nervous systems of worms and snails are situated on their belly sides. As well as this, the nerves of gastropods are all connected to one big ganglion which controls the nerves to every part of their body. Although the nervous system of gastropods aren't as complex or as smart as cephalopods, they still work well and help