Placoneis protracta (Grunow) Mereschkowsky, 1903 Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Chromista phylum Ochrophyta class Bacillariophyceae order Naviculales family Naviculaceae genus Navicula species Navicula protracta Name Homonyms Placoneis protracta (Grunow) Mereschkowsky, 1903