Drily

Tom, desperate, howled: "Mary! Where are you?" from the very left edge of the sentence. "I fear I'm from now on, fully at the opposite from you" drily retorted Mary.

Source: tatoeba (1076557)

“Anybody been here, Sammy?” asked Mr. Weller senior, drily, after a long silence.

Source: wiktionary

Füssli […] gives an account of the painter which is largely occupied with a consideration of his masterpiece, the ‘Battle of Waterloo.’ He comments upon the prominence given to Wellington in the picture, and rather drily remarks […] that the rearward position assigned Blücher is not an ungraceful tribute to Germany ! the intention undoubtedly being ‘der deutschen Bescheidenheit ein Compliment zu machen.’

Source: wiktionary

It was not until 1889, however, that Nat Goodwin's talent as a comedian of the “legitimate” type began to be recognized. From that time he appeared in a number of plays designed to display his drily humorous method, such as Brander Matthews' and George H. Jessop's A Gold Mine, Henry Guy Carleton's A Gilded Fool and Ambition, Clyde Fitch’s Nathan Hale, H. V. Esmond's When We Were Twenty-one, &c.

Source: wiktionary