I've heard a lot of people discussing about the difference from a Rhodesian and a Bulldog. Someone say that a Bulldog has a diamond shank and the Rhodesian has a round one. I stay with the Castello theory: the Bulldog has a stacked bowl; the rhodesian has a squat and thicker bowl. Both can have a diamond or round shank and both could be lightly or full bent.
The Rhodesian shape has a peculiar bowl: it is made of two truncated cones which meets about at 3/4 of the bowl. In this point the pipemaker is used to make two lines all around the bowl. We can also find Rhodesian pipes which does not has the lines. The bowl is usually lightly canted, but it is true only on the very classic shape. The shank has a diamond section and the stem is taper in the original classic shape, but we can find several Rhodesian with saddled mouthpiece. Army mount style is also quite common.

CONNECTED SHAPES

The Rhodesian has a Bent version which could have 1/16, 1/8, 1/4, 1/2 or full bent stem.

The Bulldog is feautured by a peculiar bowl which is made by two truncated cones. The shank has usually a diamond section.

The Bulldog is also made in the Bent version with 1/16, 1/8, 1/4, 1/2 or full bent stem.