"Diagram of the heart and branchial arches in Protopterus (one of the Dipno). pre.c., precaval vein,…
"Diagram of heart and branchial arches in Ceratodus (one of the Dipnoi). a.b., air bladder (lung); p.a.,…
"Diagram of the heart, the branchial arches, and the principal veins in the Teleosts. Ventral view.…
"Diagrams of the structure of the heart in the lower Vertebrates. A, primitive condition; B, the position…