ClipArt ETC
"Lung of Ceratodus, opened in its lower half to show its cellular pouches. a, right half; b, left half; c, cellular pouches; e, vena pulmonalis; f, arterial blood-vessel; oe, esophagus, opened to show glottis." — Encyclopedia Britannica, 1893

Ceratodus Lung

"Lung of Ceratodus, opened in its lower half to show its cellular pouches. a, right half; b, left half;…