• 1) A geographically widespread phylum of approx 300 spp.; marine deposit feeders

• 2) The bizarre body plan includes:
  
  a) two coeloms (small- tentacles, large- trunk)
  b) a completely invertable head end! (introvert)
  c) a crown of tentacles surrounding mouth is used for collecting food particles from adjacent surfaces
  d) an unusual gut (terminal mouth, mid-dorsal anus)

• 3) Related to molluscs by several distinctive characteristics:
  
  a) molluscan cross (apparent in the 64-cell stage)
  b) an eversible scraping buccal organ in the larva; some think it may be related to the radula in gastropods
  c) a creeping muscular lip; some think it may be related to the creeping foot in benthic molluscs

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