"Diagram of the heart and the branchial arches in Mammals. A dotted outline of the arches of the Fish is drawn for ready comparison. The auricles are represented in a posterior position...a, aorta; au., auricle; c, carotid; d.a., dorsal arteries; j, jugular veins; s.v., sinus venosus; v, ventricle." -Galloway, 1915

Mammal Heart

"Diagram of the heart and the branchial arches in Mammals. A dotted outline of the arches of the Fish…