I think he's talking about the sexual immorality of the women who do wear men's clothing (venereous inclination and all that), although it's kind of weird, because both Medea and Circe were known for enticing men… But Circe, at least, I think was usually associated with lust (i.e. being allegorically turned into a beast), so maybe it is purely symbolic. Although it does make it sound like he's complaining about men who wear women's clothing, too.