Figure 4. Pholcus J in Studies on spider respiration and circulation by Victor Willem

Figure 4. Pholcus J, sagittal view (X 15). k, right chelicera; n, sub-esophageal nerve ganglion; I, II, III, ostia; ap, posterior artery; 2, 3, lateral conjunctive lamellae; 3, posterior lateral artery; a, anus; g, genital opening, and above it, hypocardial ligament; Sp, pulmonary sinus. [I have represented on Fig. 4, with arrows, the direction and relative size (at a scale 25 times larger than the drawing itself!) of the movements of some points in the middle region of the body. The three fine lines indicated for the posterior half of the abdomen correspond to the complex vertical oscillation of the abdomen; the bold lines correspond to local elementary deformations.].