</noinclude> [[Image:Penion cuvieranus cuvieranus.JPG|thumb|250px|''Penion cuvieranus cuvieranus'', showing its '''siphonal canal''' to the left.]] In some sea snails, (marine gastropod molluscs in the infraorder Neogastropoda), the animal has an anterior extension of the mantle called a siphon, through which water is drawn into the mantle and over the gill. This siphon is a soft fleshy tube which also serves to "smell" or "taste" the water in order to locate a possible source of food.