Pellucidar

Pellucidar is a series of seven novels written by Edgar Rice Burroughs, written and taking place in the 1910s, 1920s and 1930s. In this Verse, the Earth is hollow and there is another world on the inside, called Pellucidar, inhabited by dinosaurs and others monsters as well as primitive humans.

The complete series is composed of the following novels, the first two of which are in the public domain:

At the Earth's Core. Published in serial form in April, 1914. Book form published in July, 1922.
Pellucidar. Published in serial form in May, 1915. Book form published in September, 1923.
Tanar of Pellucidar. Published in serial form from March to August, 1929. Book form published in May, 1930.
Tarzan at the Earth's Core. Published in serial form from September, 1929 to March, 1930. Book form published in November, 1930.
Back to the Stone Age. Published in serial form from January to February, 1937. Book form published in September, 1937.
Land of Terror. First published in 1944. Unusually the book was its original form.
Savage Pellucidar. Collects four Pellucidar short stories. Three from 1941 and 1942, and one previously unpublished story. The collection was first published in 1962.

Several Pastiche novels followed.

The following tropes are common to many or all entries in the Pellucidar franchise.
For tropes specific to individual installments, visit their respective work pages.

All Animals Are Dogs: With a Hyaenodon, no less. Innes even calls it a dog!
- To be fair, David isn't a paleontologist, and just looking at the thing, it's an easy mistake to make.
Beneath the Earth
Cannot Spit It Out
Canon Welding: The fourth book, Tarzan at the Earth's Core, quite clearly defines the Tarzan and Pellucidar novels as part of the same continuity, with the usual heroes teaming up with Tarzan and his allies for a Crossover.
Contrived Coincidence
Culture Clash
Deadpan Snarker: David Innes.
Damsel in Distress
Drill Tank: The "iron mole".
Duel to the Death: David Innes versus Jubal the Ugly One in At The Earth's Core.
Everything's Better with Dinosaurs
Everything's Better with Princesses: Dian the Beautiful.
Evil Albino: The Gorbuses are a subterranean race of cannibalistic albinos who are apparently resurrected surface-world murderers.
Endless Daytime: As Pellucidar is a Hollow World that has a sun at the centre, it is always noon no matter where you are.
Frazetta Man: Sagoths, Ape Men, Beast Men...
Gadgeteer Genius: Abner Perry, inventor of the Drill Tank that takes him and David Innes to Pellucidar.
Hollow World: The Earth is hollow.
Hypnotize the Princess: The Mahars of Pellucidar hypnotize everybody.
I Owe You My Life: David Innes saves Ja of the Mezops in At The Earth's Core.
Literary Agent Hypothesis
Lost World
Made a Slave: David Innes is enslaved (briefly) by the Sagoths, joining Dian the Beautiful and others who are already in a slave train in At The Earth's Core.
The Magnificent:
- Dian the Beautiful.
- Dacor the Strong One, Ghak the Hairy One, Hooja the Sly One, Jubal the Ugly One... etc.
Mighty Whitey: The people from the surface who come to Pellucidar. Something of a variant, as there are other white people in Pellucidar; the surface dwellers are (generally) mighty because of their more technologically advanced culture.
- Except for Tarzan. The Jungle Lord needs no technology to show the cavemen who's boss.
Nubile Savage: Dian the Beautiful. All of her people, too, the Tribe of Amoz. Also their neighbors, the people of Sari.
Pirate: The Korsars (corsairs) of Pellucidar.
Reptiles Are Abhorrent: The Mahars, a race of sentient psychic pterosaurs who appear as the first major villainous race in the series.
Traveling At the Speed of Plot: Some of the stories played with the notion of time as highly variable in a situation where there's no day-night sequence to measure it by. David Innes was once accidentally separated from his comrade and went through several weeks worth of adventures. When they were reunited, he discovered that since his friend hadn't needed to exert himself to anywhere near the extent David did, for him less than an hour had passed.