Sawtooth Pen Shell (Marine Invertebrates of Jekyll Island, GA) · iNaturalist

Photos of Noble Pen Shell (Pinna nobilis) · iNaturalist

Photos of Cart-Rut Shell (Dicathais orbita) · iNaturalist

Photos of Pearl Kite (Gampsonyx swainsonii) · iNaturalist

Photos of Stiff Pen Shell (Atrina rigida) · iNaturalist

Cannonball Jelly (Marine Invertebrates of Jekyll Island, GA) · iNaturalist

Sea Pens (Superfamily Pennatuloidea) · iNaturalist

Photos of Amber Pen Shell (Pinna carnea) · iNaturalist

Photos of Amber Pen Shell (Pinna carnea) · iNaturalist

Photos of Cart-Rut Shell (Dicathais orbita) · iNaturalist

iNaturalist on Instagram: Our Observation of the Day is this sea pen (potentially Balticina willemoesi), seen in the #UnitedStates by crabsandshrimps! More details at: #marinescience #cnidaria #nature