How did the guests dress?

Prince Prospero, the ruler of a land that is being decimated by a plague called the Red Death, decides that "the external world could take care of itself," and he calls a thousand of his most hearty and healthy friends to accompany him to a distant abbey that he has fortified against the disease.  In the fifth or sixth month of their seclusion, the Prince throws a huge party, a "masked ball" of unusual splendor. His guests dress in masquerade: elaborate costumes that cover both their bodies and faces.  
The narrator tells us that Prospero's own "guiding taste" helped to attire the masqueraders.  He says, 

Be sure they were grotesque.  There were much glare and glitter and piquancy and phantasm. . . . There were arabesque figures with unsuited limbs and appointments.  There were delirious fancies such as the madman fashions.  There were much of the beautiful, much of the wanton, much of the bizarre, something of the terrible, and not a little of that which might have excited disgust.

From this description, it is difficult to tell exactly what the masqueraders are dressed as.  An adjective like grotesque could refer to a combination of the human and animal in such a way that it achieves absurdity or even ugliness.  Piquant implies that the costumes were provocative; phantasm implies that they are fantastic, illusory, or even ghostly.  Arabesque alludes to the idea that the costumes are ornamented with flowers, foliage, or fruit and are very intricate and elaborate in design.  The guests are described as moving "dreams" that seem to defy the imagination to come up with something more creative, but the strangeness of disproportionate limbs and the madness of the designs is simultaneously repugnant and off-putting.  The guests' costumes elicit feelings of pleasure and disgust at the same time.