The sheriffs in several of Maryland's rural countries wield nearly as much power today as their namesakes did in the England of King Richard II. They run the police force and the jail. They serve warrants, eviction and extradition papers. They guard the county courtrooms.

However, in the more populous counties - including Prince George's, where Sheriff Don Edward Ansell was indicted yesterday - the functions of the office have been severely narrowed over the last decade.

There are separate county police departments in Baltimore, Montgomery, Anne Arundel and Prince George's to patrol the roads and conduct the criminal investigations. Montgomery County has a separate department of corrections.

Prince George's County, after years of debate, moved this year to remove corrections from the sheriff's department. The reorganization plan was developed while the grand jury was investigating Sheriff Ansell, but county officials said it was not taken as a punitive action against Ansell.

"It has nothing to do with that," said County Executive Winfield M. Kelly Jr."It has to do with getting a better return on your dollar."

For whatever reason, the sheriff of Prince George's County is no longer a man of many responsibilities. He oversees the transporting of prisoners, the guarding of courtrooms and the serving of legal papers. "It is basically a job that anyone could do," said one county official. "That's the way it should be."

The sheriff's department budgets in the counties are as diverse as the duties. In rural Calvert County, where the sheriff andd six assistants serve about 20,000 citizens, the department is run for about $80,000 per year. The 278-employee Prince George's force has a budget approaching $5 million, with about three out of every five dollars going to the county jail.

The one thing all 23 sheriffs have in common is that they are products of the political system. They run for office every four years on party tickets. As often as not, they come up through the ranks of politics rather than law enforcement. Ansell, for instance, never served in a sheriff's office until he was elected in 1970, although he had been a state trooper.

One member of a political screening committee, when asked what he looked for in a sheriff candidate, responded only half in jest: "The most important thing is the resonance of the name. It has to have a strong ring to it. It has to sound like authority."

For a brief period in the late 1960s, Prince George's had a sheriff who took his authoritative title quite seriously. This sheriff, William J. Kersey, established a deputy reserve corps that was, in effect, a 500-man posse. It included an "air wing" of privately owned helicopters and planes.