title: The blood system of the flabelligerid polychaete Flabelliderma commensalis (Moore).
mesh_terms: D000818:Animals; D001775:Blood Circulation; D001808:Blood Vessels / Q000033:anatomy & histology*; D006321:Heart / Q000033:anatomy & histology*; D008854:Microscopy, Electron; D012617:Sea Urchins / Q000033:anatomy & histology*