Figure 3 in Studies on spider respiration and circulation by Victor Willem

Figure 3. Schematic transverse section of the heart of Araneus at the level of the 2nd pair of ostia; v, a muscular lip of the ostium uniting with the corresponding lip on the opposite side to form an incomplete transverse veil; e, epicardial ligaments; p, peripyle; P, dorsal insertion of the anterior abdominal pillar; c, commissural ligament, presumed to be brought into the transverse plane; a, lateral artery; h, hypocardial ligament.