<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="SC-324" name="Serpulid Substrate" parent="SC-307" scope="Substrate Subclass: Biogenic substrate layers with conglomerated structures or broken particles that are primarily composed of cemented calcareous worm tubes produced by serpulid worms, e.g., Serpula."/><bt><term thcode="62" code="SC-307" name="Worm Substrate" parent="SC-301" scope="Substrate Class: Biogenic Substrates that are primarily composed of the cemented or conglomerated calcareous or sandy tubes of polychaetes or other worm-like fauna. ..."/><term thcode="62" code="SC-301" name="Biogenic Substrate" parent="SC-C003" scope="Substrate Origin: Substrates where percent cover of non-living Biogenic Substrate exceeds percent cover of both Geologic Substrate and Anthropogenic Substrates, when all are considered separately. ..."/><term thcode="62" code="SC-C003" name="Substrate" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt><nt><term thcode="62" code="SC-354" name="Serpulid Hash" parent="SC-324" scope="Substrate Group: Substrate that is dominated by the calcareous tubes of serpulid worms, with a median particle size of 2 millimeters to &lt; 64 millimeters (Granules and Pebbles)."/><term thcode="62" code="SC-352" name="Serpulid Reef Substrate" parent="SC-324" scope="Substrate Group: Reef that is primarily composed of cemented or conglomerated calcareous worm tubes, with a median particle size of 4,096 millimeters or greater in any dimension."/><term thcode="62" code="SC-353" name="Serpulid Rubble" parent="SC-324" scope="Substrate Group: Substrate that is dominated by cemented or conglomerated calcareous worm tube Rubble, derived from serpulid worms, with a median particle size of 64 millimeters to &lt; 4,096 millimeters (Cobbles and Boulders)."/></nt></descriptor>