In the beginning of the episode, Alfred says "excellent, Master Robin" while Dick Grayson is out of "uniform" playing the drums.
Alfred: Excuse me, sir, your crate is safely aboard.
Bruce: Thank you, Alfred.
Barbara: I saw that immense thing with your name stenciled on it on the pier. What in the world do you have in it?
Bruce: Just because we're traveling, I don't think that Dick should neglect his studies, so we've brought along a thousand key works of literature, his biological specimens, and also his own desk.
Dick: Yes, I expect to study hard.
Barbara: It's a good thing you're going by ship, Dick.
Penelope: It's supposed to be a finishing school. We're being finished all right, with an M.S. degree.
Penelope: Mistresses of Shoplifting. That's what Lady Peasoup meant about using our wits.
Robin: Holy contributing to the delinquency of minors!
Robin: Holy show-ups, that Batgirl!
Batman: She does make a colorful reinforcement all right, although I don't want her to think we can't fight our own battles.
Robin: Gosh, no, Batman! But what do you suppose she's doing in Londinium? And where do you suppose she went?
Batman: I can't answer the first question, Robin, and I've never been able to answer the second.
Bruce: (to Dick playing the drums) Cool it, Ringo.
Bruce is referencing the drummer of the British band The Beatles.
Ireland Yard is an allusion to the Metropolitan Police Service of London, UK called Scotland Yard.