While "Lieutenant Murray" was a pen name of Maturin M. Ballou, there is nothing to connect him with the Beadle author "Captain Murray." It has been suggested that "Captain Murray" was Captain Charles A. Murray, who wrote "The Trapper's Bride" and "The Prairie Bird" but, since there is no given name, there is no direct evidence to connect these two.
Dime Novels. No. 258, 260, 481, 491