A Complete Guide to Heraldry by Arthur Charles Fox-Davies

2. ("Post hos insignem--serpentibus hydram."--Lib. vii. lines 655-658.)

"Next Aventinus drives his chariot round The Latian plains, with palms and laurels crown'd. Proud of his steeds, he smokes along the field; His father's hydra fills his ample shield; A hundred serpents hiss about the brims; The son of Hercules he justly seems, By his broad shoulders and gigantic limbs."