Seashell Identification – Common Atlantic Shells

Some common long shells found on the beaches I frequent are the pen shell, jackknife clam and stout tagelus.

Pen shells often have an iridescent shine and the ones I find are usually just pieces. An unbroken shell can be close to a foot in length.

According to my Seashell Book, there are three types of pen shell: the sawtooth, stiff and half-naked. Pretty weird names. Contrary to what you might think, the sawtooth is the smoothest looking. The other two have vertical ridges going the length of the top “fan” part of the shell.

The Minor Jackknife Clam Shell

This long, whitish shell is the Minor Jackknife clam. My kids used to call it a fingernail shell. It is also a razor clam.

pen shells and jackknife clam shell — Jackknife clam and pen shells

The longish and wider shells shown below next to my eye glasses are stout tagelus. These are also known as “short razor” clams.

stout tagelus clam shell — Stout tagelus clam shells

Pen shells are related to mussels which are not the prettiest of shells. I have one in my photo below along with a tagelus.

Florida seashells — Broken Crown conch, mussel, clam, tagelus, dosinia, little shark’s eye, and tiny marsh periwinkles (one sits on top of a penny).

Ribbed mussel shell — Open and empty mussel shell

Latest from the Blog

crown conchs, hermit crab, coffee melampus

The Coffee Melampus Shell Identification

The Coffee melampus shell is small and roundish. The one I photographed is brown in color with horizontal stripes. The hermit crab which was carrying the shell, was hidden down under the large crown conch. It’s one of those small shells which would be easy to overlook while beach-combing. The living crown conchs seemed to […]

The Bruised Nassa Is a Tiny Sea Snail

The Bruised Nassa shell is so small that it would be very easy to miss on a sandy beach. They only grow to be 3/4 of an inch and this one is about a half inch. Luckily there was no hermit crab inside so I brought it home to get these photos. I found this […]

Horse Conch Called “Knobless Wonder”

When a reader left me a comment about my big horse conch photo, saying that it looked unusual, I began to look more closely at the horse conch photos I had taken and compare them with photos online. Apparently the horse conchs I usually find are called “knobless wonder”. This is because they lack the […]