Planorbarius corneus
Planorbarius corneus , common name the great ramshorn , is a relatively large species of air-breathing freshwater snail , an aquatic pulmonate gastropod mollusk in the family Planorbidae , the ram's horn snails , or planorbids , which all have sinistral or left-coiling shells . 
<triplet> gastropod <subj> mollusk <obj> parent taxon