Allusion to 'Janian...' WTF?

Question

"A true Janian reply!" (C. Bronte's "Jane Eyre" chapter 22)

Rochester says this to Jane, though I know he's not refering to her when he says "Janian" in response to her saying, "I have been with my aunt, sir, who is dead."

And if you know a lot about literature, I have a lot more question on allusions... so...

Answer 1

"And this is Jane Eyre? Are you coming from Millcote, and on foot?
Yes--just one of your tricks: not to send for a carriage, and come
clattering over street and road like a common mortal, but to steal
into the vicinage of your home along with twilight, just as if you
were a dream or a shade. What the deuce have you done with yourself
this last month?"

"I have been with my aunt, sir, who is dead."

"A true Janian reply! Good angels be my guard! She comes from the
other world--from the abode of people who are dead; and tells me so
when she meets me alone here in the gloaming! If I dared, I'd touch
you, to see if you are substance or shadow, you elf!--but I'd as
soon offer to take hold of a blue ignis fatuus light in a marsh..."

Rochester -is- referring to her, and being rather sarcastic about it. Kind of like calling someone a princess because of how they act.