The Apple and its Variants
The Apple
The Apple is similar in proportions to the Billiard, but with a voluptuous, rounded, apple shaped bowl. An apple can be fitted with either a tapered or a saddle stem, or, even an army mount stem, but, to my eye, the perfect apple has a tapered stem.
Pictured above, top to bottom, a GBD Virgin small apple, a Comoy Grand Slam medium apple, and a large Jean LaCroix Carmel, made for Drucquer & Sons in the late 1970''s. (It's only coincidence that this is a Carmel apple...)
The Prince
If the Apple's bowl is flattened a bit, the shank shortened and thinned, the stem lengthened, and often slightly bent, the Prince, or Prince of Wales shape results. Alleged to have been originally designed in the 1920s by Loewe's in London for Edward Prince of Wales, later Edward VIII, the Prince is sophisticated and graceful, reflecting both Edward's impeccable sense of style and the elegance of the period.
Above, top to bottom: Dunhill Root DRC Prince (no shape number!), Dunhill Shell FET Straight Prince, Dunhill Shell Army Mount Prince from the 1920s with no shape number.
The Author
The bowl of the Author is similar to that of the Prince, but the shank is heavier, and is designed for a 1/4 bent stem. The Comoy, pictured at the top, is, to my eye, the perfect Author. Some would put this shape in the same class as the Bent Bulldog or Rhodesian, and, indeed, there are similarities. The roundness of the bowl seems to be the defining characteristic, however, so I've stuck them in the Apple "genus."
Above, top to bottom: Comoy Tradition, Sasieni Four Dot "Ashford", Orlik.