challenge: What species is not one of the original species included in the genus Glabella?
  
  A. Marginella glabella (Linnaeus, 1765)
  B. Marginella glabella (Linnaeus, 1758)
  C. Marginella glabella (Linnaeus, 1757)
  D. Marginella glabella (Linnaeus, 1760)
  Answer: 