Planorbella trivolvis
Planorbella trivolvis is a species of freshwater air-breathing 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> snail <subj> gastropod <obj> subclass of <triplet> gastropod <subj> mollusk <obj> parent taxon