pectinibranchia: large order of gastropods comprising univalve mollusks that have a single gill resembling a comb
animal order: the order of animals
whitlowwort: any of various low-growing tufted plants of the genus Paronychia having tiny greenish flowers and usually whorled leaves; widespread throughout warm regions of both Old and New Worlds; formerly thought to cure whitlows (suppurative infections around a fingernail)