What in the heck is a Hyalopterous Lemure?
»Hyalopterous« is a fancy word meaning »having glassy or transparent wings.«
The word »Lemure« is quite obscure; it shows up on dictionary.com as »lemures« (LEM-yur-eez), which were »spirits or ghosts of the departed.«
A ghost with glassy wings… sounds good so far.
Of course, the poor artist—Richard Thomas—was not as well versed in minor Devils (or Latin), and painted what he thought the art was supposed to be… a lemur. That's right, a small, nocturnal primate from Madagascar with big eyes and a bushy tail. Who can blame him?
He did paint glassy wings on, so he got the hyalopterous part right.