Figure 6. Screen shot of Advanced Taxonomic Search page, where the user can progressively narrow the selection based on taxonomic levels.  Each clade (or level) chosen will decrease the number of items in the pulldown lists to reflect the choice made.  For example, if the user selects only Genus: Madrepora, the Species pulldown list will comprise only carolina and oculata and the pulldown lists for the clades above Genus will comprise only the one appropriate name.  The graphic of clades to the right of the pulldown fields changes color as the user selects taxonomic levels on the left.