Description
An illustration of the median longitudinal section through anterior end of the sea lamprey. "a.v.o, Antrio-ventricular opening; br, Brain; br.o, Internal opening of gill sac; d.a, Dorsal aorta; d.c, Ductus cuvieri; h.v, Hepatic vein; i.j.v, Inferior jugular vein; N, Notochord; oes, Esophagus; olf, Olfactory organ; oc, Pericardium; p.c.v, Left posterior cardinal vein; pit, Pituitary tube; V, Ventricle; v, Velum." (Britannica, 1910)
