[74] Lacus is illustrated by Pliny Ep. 9. 8 (on the source of the Clitumnus): “Eluctatusque (fons) facit gurgitem, qui lato gremio patescit purus et vitreus.” Serv. says “Lacus est quoddam latentis adhuc aquae receptaculum, et dictus lacus quasi lacuna: ex qua erumpens aqua facit fontem: qui cum fluere coeperit alveum facit.” ‘Miserantem incommoda nostra’ gives the reason for Aeneas' prayer, serving also to remind the god of his promise: ‘pulcherrimus’ expresses Aeneas' gratitude.