Scientific Name for a slug?

Dear Jaykada,
I'm afraid there is not a scientific name for a slug. Have a look at the pictures and my comments at the top of this page.

Essentially a "slug" is a snail that has lost its shell, not through carelessness, but in an evolutionary process that has occurred many times amongst the gastropod molluscs. Both in the opisthobranch sea slugs and the pulmonate land snails there are many quite unrelated families and superfamilies which have independently begun the process of "losing the shell". Gradually the shell becomes smaller, and less heavily calcified until its reaches the stage where it no longer can protect the animal from attack or from environmental problems such as drying out.

At this stage the animal has to evolve other means of defence. Land slugs produce heavy mucus from their skins to prevent desiccation (drying out) and they are often well camouflaged, perhaps as a protection from attack. Most also become nocturnal, as they are less likely to be seen by predators or dry out at night. The many different ways opisthobranchs have evolved to protect themselves can be found in the Sea Slug Forum. Have a look at Opisthobranch Defence Mechanisms.
Bill Rudman.