[3] nec mirum: cf. Catul. 23.7n.
[3] utrisque: found in Catullus in the plural only here and in v. 6; and in general the plural is much more common in prose than in poetry.
[4] urbana: i.e. Romana; cf. Catul. 29.23 “urbis” (= Romae).
[4] Formiana: cf. Catul. 41.4n.
[6] morbosi: probably merely a translation of παθικοί; cf. gloss. Labb. p. 116a “morbosus παθικος´ ”
[6] gemelli: sneeringly, of their similarity in character; cf. Hor. Ep. 1.10.3 “cetera paene gemelli fraternis animis” , where, however, there is no irony.
[7] lecticulo: study-couch; ἅπαξ λεγόμενον, but the feminine lecticula occurs in this sense in Suet. Aug. 78, and the masculine is not strange by analogy with lectulus (cf. Plin. Ep. 5.5.5).
[7] erudituli: Caesar was not only a historian, but a grammarian (Suet. Iul. 56; Cic. Brut. 72.253) and a poet (Suet. l.c.; Tac. Dial. 21; Plin. Ep. 5.3.5). On Mamurra's attempts at poetry see Catul. 105.1ff.
[9] rivales socii: here it appears better to take rivales in its original implication of not unfriendly rivalry, the two friends vying with each other in the number of their mistresses; v. 9 thus completes v. 8; cf. Tac. Hist. 1.13 “[Otho erat] gratus Neroni aemulatione luxus” .
[10] The first and last verses are identical also in Catul. 16.1ff., Catul. 36.1ff., and Catul. 52.1ff.