“More and more snow fell and the hut was more and more hidden under the white blanket. Sometimes I noticed that the fox had gone to the top of the dome and evidently sat there for a while. Near where he had sat was a hole in the snow about half a foot in diameter and with thin ice around the edge. I found that the hole widened downward and ended on the roof of the lodge. At the bottom the hole was at least two feet in diameter and its walls were hard as ice. From this hole or chimney rose warm steam, and the twigs and mud on the roof felt warm and damp to my hand.” _The Demon of Puerto Rico_ In deep sunless ravines of Puerto Rico’s Pandura mountains dwells the demon frog. It is a ghostly voice from mountainsides strewn with great, decomposing granite boulders and so thickly covered with tropical vines and bushes that it is almost impenetrable to man. Until twenty years ago it was only a voice, for none of the strange little creatures ever had been seen. The mere sight of the animal, according to many of the natives, would be fatal. “One might as well try to bribe a mountaineer to catch a ghost as a guajone. There is a strange quality in the voice which probably is largely responsible for the superstitious dread of the mountain people,” according to Smithsonian Institution biologist Gerrit S. Miller, Jr. “It is strange enough when heard from the surface,” Miller reports, “but it becomes even more strange after one has climbed down into the irregular and dangerous openings, which prove to be much larger and more cavernous than the surface appearance, with its dense and deceptive covering of vegetation, could lead one to expect. With flashlights the frogs are easily found and caught as they crawl slowly over the damp, but not slippery surface of the granite. “To the natives they are objects of dread. One man said they were about a foot long and armed with frightful teeth. Another assured me that anybody who saw one would die shortly afterwards. No offer of money could induce the boys or men to go into the cavities in search of them.” The little creature is fantastic in appearance, chiefly due to its large protruding eyes. The edge of the eyelid is white, making a thin white line around the eye. The iris is back and gold. The skin is light brown above and nearly white underneath, but some specimens have blotches of yellow which add to the weird appearance. Living as they do in the semi-darkness of mountain gullies, little is known of the life history and habits of these strange creatures. The most notable characteristic of several specimens kept alive for observation was the peculiar singing in a liquid note repeated six or seven times. It can best be imitated by whistling. This singing is believed to be part of the courtship behavior of males. The demon frog has been given the scientific name of Eleutherodactylus cooki. It appears to have been especially adapted for life among the boulders of its restricted habitat.