Possible Clues:

• Slug with a shell
• Gastronome's gastropod
• Slow mover's cruise round pole
• Smashing Pumpkins' slow song?
• 28's food item taking seconds to secure
• Gastropod for gastronomes
• 10 ac mollusc
• Periwinkle, for one
• Sluggish sort
• Mollusk that moves like molasses