Irony in The Canterville Ghost
Similar to the "Dumb Daniel, or the Suicide's Skeleton" annotation, this is line once again exemplifies Wilde's humorous irony because it demonstrates the contrast between how readers and Sir Simon view his behavior as a ghost. Sir Simon considers himself very legitimate, but readers see that he is simply performing clichéd roles.
The commas after "Dumb Danial" surrounding "or the Suicide's Skeleton" create a grammatical construct known as an appositive, which means the information between the commas defines the preceding information, but it is often considered unnecessary because readers are familiar with the full meaning of the first information. This makes this apposition particularly ironic because it appears to signify something like “as you all know.” However, it is unlikely that many readers know Dumb Daniel is the suicide skeleton.
The phrase "of course" gives the impression that the narrator is sharing important, confidential information with the readers and confirming the ghost's actions as logical and appropriate. However, since the phrase is set between two commas, readers should note that this indicates Wilde's intention to signify the opposite meaning: the ghost's actions should be seen as absurd and playing into the classic tropes of ghost stories.
Located on the western coast of the United States, California acquired its statehood status in 1850. However, in the 19th century it still had a strong mental association with the lawless frontier period of the American Wild West. Mr. Otis's "Californian etiquette" is an excellent example of Wilde's use of irony because holding someone at gun point and demanding that they raise their hands above their heads are certainly not considered appropriate behavior.
The ghost's response is a good example of verbal irony as he responds to Virginia's satirical comment in kind. Sir Simon equates ruins with the United States' navy and curiosities with American manners, implying that the US has never matched the sea power of England nor understands true civility like the English.
Wilde is likely pointing out the irony in how even though the US doesn't have royalty or an aristocracy, the dream of becoming royal, a prince or princess, still persists in the popular imagination of many young people. The ending to The Canterville Ghost represents this as well, with the young heroine being rewarded with jewels, a handsome prince, and a happily ever-after.
Mr. Otis's statement reinforces the culture clash between American and English values. Wilde satirically portrays Mr. Otis as someone who cares little for "such vain gauds and toys" and believes that they are something that should only belong to the British aristocracy. Further irony in this statement is found in Mr. Otis's declaration that he and his family believe in the "principles of Republican simplicity"; while professing to not need gaudy jewels, Mr. Otis lives in a massive mansion with servants.