A great title. As usual I came across this whilst searching for something else. Something about this was familiar but I haven’t read the book, and I suspect it will be one of those where the title proves a lot more evocative than the narrative. The author was a Canadian writer, James De Mille (1833–1880), and this novel of all his works is the most well-known for its predating more famous fantasy novels by H. Rider Haggard. Wikipedia has a précis:
The satiric and fantastic romance is set in an imaginary semi-tropical land in Antarctica inhabited by prehistoric monsters and a cult of death-worshipers called the Kosekin. Begun many years before it was published, it is reminiscent of Edgar Allan Poe’s The Narrative of Arthur Gordon Pym of Nantucket and anticipates the exotic locale and fantasy-adventure elements of works of the “Lost World genre” such as Arthur Conan Doyle’s The Lost World, Edgar Rice Burroughs’ The Land That Time Forgot, as well as innumerable prehistoric world movies based loosely on these and other works. The title and locale were inspired by Edgar Allan Poe’s Ms. Found in a Bottle.
The illustrations are by Gilbert Gaul from the story’s serialisation in Harper’s Weekly in 1888. The best one shows a ride on a huge pterodactyl-like creature called an athaleb that makes me think of the ride on the shrowk in David Lindsay’s A Voyage to Arcturus, albeit without the erotic fervour of Lindsay’s episode. Fervour or no, the road to Lindsay’s philosophical weirdness begins with early novels such as this. De Mille’s book may be browsed here or downloaded here.