flatworm, platyhelminth
["yellow lady's slipper, yellow lady-slipper, Cypripedium calceolus, Cypripedium parviflorum", 'platypus, duckbill, duckbilled platypus, duck-billed platypus, Ornithorhynchus anatinus', 'sturgeon', 'tiger shark, Galeocerdo cuvieri', 'envelope', 'slide rule, slipstick', 'rule, ruler']