J. Alden Mason's 1914-1915 field trip to Puerto Rico resulted in a vast collection of songs, riddles, and folktales, published regularly over the next fourteen years in the Journal of American Folklore. The rich harvest of tales included some seventy Juan Bobo stories. "Juan Bobo and the Riddling Princess," like many other Puerto Rican mächen, is a composite. Translating the story presented interesting challenges. I had to try for a storyteller's voice in English that would match the inspired silliness of the narrative voice in Spanish. The key word in the story, adivinar, defied translation. Puerto Rican idioms and the riddles themselves presented further challenges.