Can you identify this 3x4 black plate with studs only going down the middle?
You should be able to find this piece by looking up any of the collectible minifigures on Bricklink and looking at the set inventory.

This piece is the Tile, Modified 3 x 4 with 4 Studs in Center (88646). 

It is classified on Bricklink under the category 'Tile, Modified'.