Pokemon number 151 is Manaphy - you can only see it by reading the book on the table of Mr. Backlot's room (far right door) in the Pokemon Mansion.
Mew is, as far as I know, unobtainable apart from with an Action Replay in Platinum.
I'm sure I can conjure one up though, so if you're that desperate for a Mew exchange friend codes and I'll send you one if it lets me.
in the sinnoh reigon chatot in the national exeggcute
Swinub
Happiny in the sinnoh pokedex and in the national pokedex number 96 is drowzee
170=glacion 190=dusclops
Number 46 un Sinnoh dex is Wormadam. I think it evloves from Burmy, Look it up.
Swinub is #203 in the Sinnoh Dex in Pokémon Platinum.
It is Leafeon.
Wormadam
wormadam
Dusclops
its a cascoon
happiny
Vaporeon.
porygon
Rotom
Dusclops
Glaceon