leaena: perhaps the first occurrence in Latin of the Greek word for the early leo femina (Plaut.) and lea (Varro).
Libystinis: rare form of the adjective; cf. Catul. 7.3 “Libyssae” .
[2] latrans: etc. Catullus, like most, if not all, of the Latin poets that mention her, evidently thinks of Scylla with a woman's body ending below in a group of fierce dogs; but Hom. Od. 12.85ff., as might be expected in an earlier conception, describes her as a monster entirely without human form.
[4] in novissimo casu: at his supreme trial; the phrase may well imply apprehended death; cf. Tac. Ann. 12.33 “novissimum casum experitur” (i.e. tries the forlorn hope).
[5] contemptam haberes: cf. Catul. 17.2n.
[5] nimis: cf. Catul. 43.4n.
