For all of you who now wonder what the æther Euthyneura are, it is a taxonomic clade of snails and slugs, which contains quite a number of species in a range of habitats. This, however has little to do with Steampunk and more with biology.
I am also aware, snails and slugs wearing Steampunk gear have little to do with evolution. I strongly doubt, gastropods would actually evolve in such a way as to be able to invent and use technology.
Well, the concept still makes for quite sweet pieces of art, such as can be found at Malice in Underland. Here is a fine choice of some of their gastropodic creations:
Strange and wonderful, but this is what Steampunk is all about! There is more on the site I linked to above. I suggest you go and tae a look.