Lugosi stand-in?
There's a scene in which a bat transforms into the human form of Count Mora before our eyes. The caped vampire then rushes at the viewer/camera (representing the point of view of the butler and maid, who have been tasked by the Professor with placing bat thorn in every room).
This image of Count Mora does not look quite like Lugosi, who was 52 at the time (b. Oct. 1882; film released in April 1935). It looks like a younger man (we see him only for a few seconds, but I think he would have made a good Dracula).
Can anyone confirm?