Mollusks are assumed to have an open circulatory system where the vessels and blood come into direct contact with the tissues and cells. However, in studies regarding the circulatory system of the foot in Megathura crenulata, this observation is left up for debate. This animal has attracted attention recently because it possesses hemocyanin, a blood protein which has been linked to increasing a patient?s immune system. However, little evaluation has been given to direct study of the circulatory system of the animal. Through an ultrastructural analysis of the foot through scanning and transmission electron microscopy, vessels were observed possessing an incomplete or absent endothelium. Furthermore, the spatial arrangement of the blood vessels were identified by injecting the animal with mercox, providing a plastic cast. Finally, this study allows for further investigation into the different sized vessels of the foot and hemocytes present , the role of these vessels in the operation of the foot and eventually the filters in the foot that keep the circulating fluids free of pathogens.