Expressive means and Stylistic devices

The author uses a lot of stylistic devices for example: epithets, metaphors, similes, personification  , oxymoron and zeugma.   

Epithets : scarifying retrospect, odorous masses, well-bred voices,drawling words ,  hopeless point, poor  consolation, innermost, unmitigated, arid unbedecked self, swift, limpid, upward look   

Metaphors :  garbs of pretence and egoism, the ruins of his self-conceit..

Similes : white favors like stars; as a desert drinks the rain; fluttered like a snared bird.  

Oxymoron: sullen exultation.

Personification : desert drinks the rain .

Zeugma:  garlicky, cockroachy banana steamer.

As for syntactical stylistic devices, O.Henry uses ellipsis, aposiopesis , parallelism and repetitions.

 Ellipsis : "A present," said Trysdale, "from a friend. Know the species?"    

Aposiopesis: But why...; If...

Parallelism:    He could have sworn, and he could swear now.        

 Repetitions :  “So childlike and so worshipful, and (he would once have sworn) so sincere”;”How glad, how shy, how tremulous she was! How she fluttered”