Abstract
The digestive gland (midgut gland, hepatopancreas) of the American lobster, Homarus americanus (Decapoda: Nephropidae), is permeated with terminal arterioles of the hepatic artery. Fixed phagocytes associated with the terminal hepatic arterioles removed two types of non‐biogenic, foreign particles (carbon particles and latex beads) that were injected into the blood. These cells play an important role in the cell‐mediated immunity of lobsters.