Wagner, the Wehr-Wolf, by George W. M. Reynolds. New York: Hurst & Company, undated.
This gothic tale is considered by many to be the first modern werewolf story. Serialized originally in 1846-47, this undated edition produced ca. 1875(?). I don’t believe it is the same as the 1975 Dover book, as that one has 160 pages and this one has 374.
A random paragraph:
In the brilliantly lighted apartment, to which we have already introduced our readers, the Countess Giulia receives her lover, the dissipated but handsome Marquis of Orsini; the bandit-captain is concealed behind the richly-worked tapestry; and at the door—not the little private one—of that room, an old man is listening; an old man whose ashy pale countenance, clinched hands, quivering white lips, and wildly rolling eyes indicate how terrible are the feelings which agitate within his breast.
George W. M. Reynolds (1814-1879) was a newspaper publisher and wrote several fantastical “penny dreadfuls.” The most famous is probably Mysteries of London.