Sawtooth Pen Shell (Atrina serrata) · iNaturalist

Photos of Stiff Pen Shell (Atrina rigida) · iNaturalist

Photos of Stiff Pen Shell (Atrina rigida) · iNaturalist

Please confirm if this pen shell is Atrina penna (Reeve, 1858) or Atrina serra (Reeve, 1858)?

Genus Atrina · iNaturalist

Genus Atrina · iNaturalist

Genus Atrina · iNaturalist

Genus Atrina · iNaturalist

The comb pen shell Atrina pectinata (Linnaeus, 1767) here shown with a

Bivalves – floridensis

Please confirm if this pen shell is Atrina penna (Reeve, 1858) or Atrina serra (Reeve, 1858)?