Hounds are bred for the type of terrain and hunting desired. Packs with mounted followers require a different type of Harrier than those with followers on foot. Open flat country is different than rocky hills, and since many packs hunt fox and hare, different Hounds are required. Harriers still exist and appear separately in the AMHB Studbooks. Most descriptions focus on what the hound should do rather than what it should look like.
Breeding always puts soundness and quality above appearance.
Below is one standard, of unknown origin, which is at least comparable to the Harriers seen today. EYES Very bright and deeply set. A playful, lively look is truly Harrier-like. NECK Should be perfectly clean like a Foxhound's, long and lean. LEGS AND FEET Should be as much like a Foxhound's as possible.