transmission filter

i have a 02 galant with a v6 that i just bought used and i wanted to change the trans filter and flush the fluid . now where does the filter live ? i think on the later models they have the external type on the top i can see the casting for the filter boss in my transmission but obviously no filter so i orderd an internal filter which looks like it would be in the pan and when i took the pan off which sits vertical at the front no filter just the solenoid pack. there is a large cast cover about afoot in diameter on the left side forward of the axle that sits verticle is it under there?