Inner Earth #3: Tanar of Pellucidar

Tanar, that gallant adventurer amid the perils of Pellucidar, here enters into new and startling exploits. Pellucidar is in the hollow center of the earth, a world of savage men and prehistoric beasts. Here dwell the Buried People, here is the Land of the Awful Shadow, here the Korsar pirates terrorize the sea-coast towns. Reptiles of gigantic size, saber-toothed tigers, ferocious cave-bears, and huge mastodons roam the wilderness. The piratic Korsars, led by a burly buccaneer called The Cid, carry off Tanar, the young Pellucidarian chieftain, as a hostage. On the ship Tanar meets the lovely Stellara, supposed to be The Cid's daughter. In this strange world of primitive terror, he struggles for life and the girl he loves.