Internal structures of the body of a clam.

Clam

Internal structures of the body of a clam.

Internal structures of the body of a clam, side view.

Clam

Internal structures of the body of a clam, side view.

Cross section of the body of a clam, through the heart. Arrows indicate water current through the gills.

Clam

Cross section of the body of a clam, through the heart. Arrows indicate water current through the gills.

Cross section of the body of a clam, through the posterior adductor muscles. Arrows indicate water current through the gills.

Clam

Cross section of the body of a clam, through the posterior adductor muscles. Arrows indicate water current…

Digestive and excretory organs of a clam.

Clam

Digestive and excretory organs of a clam.

The nervous system of a clam.

Clam

The nervous system of a clam.

Young clam, still within the egg membrane. m, adductor muscle; t, hooks by which it attaches itself to the gills or fins of fishes; b, byssus; s, sense organs.

Clam

Young clam, still within the egg membrane. m, adductor muscle; t, hooks by which it attaches itself…

Long clam, buried in the mud. The arrows show the currents in the siphons.

Clam

Long clam, buried in the mud. The arrows show the currents in the siphons.

Hard clam; round clam; Quahog, with foot, siphons and edge of mantle extended.

Clam

Hard clam; round clam; Quahog, with foot, siphons and edge of mantle extended.

The razor shell clam has a shell somewhat resembling in shape and size the handle of a razor.

Razor Shell Clam

The razor shell clam has a shell somewhat resembling in shape and size the handle of a razor.

Structure of a clam's gill. Arrows indicate water currents through the gills.

Clam Gills

Structure of a clam's gill. Arrows indicate water currents through the gills.

Mussel; with threads by which it is attached.

Mussel

Mussel; with threads by which it is attached.

A small mollusk. Burrows in soft rocks and is frequently killed by the cold when exposed during times of low tide.

Piddock

A small mollusk. Burrows in soft rocks and is frequently killed by the cold when exposed during times…

Scallops are distinguished by the regular ribs of the shell, and by the two angular projections that widen the sides of the hinge.

Scallop

Scallops are distinguished by the regular ribs of the shell, and by the two angular projections that…

Scallop; also known as the crusader's badge. While at rest the scallop lies on the bottom with its valves widely gaped open.

Scallop

Scallop; also known as the crusader's badge. While at rest the scallop lies on the bottom with its valves…

External features of a clam shell.

Clam Shell

External features of a clam shell.

Inside of right valve of clam shell.

Clam Shell

Inside of right valve of clam shell.

Clam in natural position with foot and siphons extended.

Clam Shell

Clam in natural position with foot and siphons extended.

Mechanism for opening and shutting a clam shell, note the internal and external hinge ligament..

Clam Shell

Mechanism for opening and shutting a clam shell, note the internal and external hinge ligament..

Structure of a clam shell.

Clam Shell

Structure of a clam shell.

Numerous mussels shells packed tightly together.

Mussel Shells

Numerous mussels shells packed tightly together.