mew
In Pokemon Platinum Version, there are two Pokedex'es, the Sinnoh Dex, and the National Dex. In the Sinnoh Dex, the 151 Pokemon is Manaphy. In the National Dex, the 151 Pokemon is Mew.
151 Pokemon are in the Sinnoh dex
Regional dex-unown. National dex-tangela.
The regional Pokédex for the Kanto region has 151 Pokémon.
There are 151 Pokemon until you get the national dex
Regional Dex: Barboach Nat'l Dex: Slowbro
Unova Pokedex: Landorus National Dex: Mew
The Sinnoh Pokedex only has 151 Pokemon in it.
#151 is Manaphy. from turtwig to manphy, then national Dex is bulbasaur to arceus
Try going to www.serebii.net and find it there, because I dont know if you are asking about the national dex or the regional dex.
All in regional dex
150 on sinnoh dex 151 if you count manaphy