At the Pineville Tavern one recent morning Roger Bonner could be found at his usual post, behind the six-burner Garland, watching over what he calls, with uncynical reverence, "the trilogy."

The trilogy involves the tavern's three mainstays, so there is always a big pot of red sauce (made to the exacting Sunday-gravy standards of Pineville's owner Andrew Abruzze, who sauces the astonishingly tender ravioli with it); a milky pot of unfancified rice pudding; and a seething pot of tea-colored broth from which, in the shape of an inverted apostrophe, there juts a prehistoric-looking tail.

These are the staples, though the menu ambles on, offering crabcakes (very good in the mode of a hands-on diner), smoked turkey clubs, burgers, and salad, shellfish and pasta chalkboard specials.

The Pineville Tavern is a staple itself in this slice of Bucks County - east of Doylestown and south of New Hope - a white-and-green roadhouse, parts dating to 1742, as is evident in the stone hearth and pumpkin pine flooring.

But as the countryside fills in (though blessedly not on Pineville's immediate flank) - and the tavern itself has plans to pave the backyard for parking and add a second dining room - the trilogy has become ever more sacrosanct; and that third, tea-colored pot more intently watched.

In it this particular morning are the beginnings of the meaty, from-scratch snapper soup that Bonner has been making, typically two kettles a week, for the last 18 years here. (And for a decade before that, if you include his years at Feasterville's pregentrified Buck Hotel, and the Warwick Hotel.)

Parsing the lineage of turtle cuisine in Philadelphia and environs is an exercise in the declension of a species. In colonial times, historians recount frenzied dockside auctions for sea turtles that were delivered along with the limes, bananas and pineapple by vessels arriving from the West Indies; one tavern advertised a feast in 1815 after scoring a fresh 70-pounder.

Alas, sea turtles (or so-called green turtles) were soon in short supply. Enter the terrapin, common in the Delaware's marshes. At what point next, with terrapin dwindling, the ornery snapping turtle took its place is rather murky.

But the muddy, brown-gravy style of snapper soup (as opposed to a clearer-broth style that Deux Cheminees chef Fritz Blank recalls his grandmother making for the saloon trade in Pennsauken in the 1950s) dates back, easily, more than a century.

Each of the Bookbinders restaurants had its own version. The Union League's chef guarded its recipe zealously. Chopped hard-cooked egg was optional. Not so a good dash of dry sherry.

But paralleling the fate of the turtles themselves, the habitat for snapper soup has been shrinking. The "turtle spice" McCormick once made has been discontinued. Bonner now orders a custom blend of coriander, allspice, cloves, anise, savory, sage and bay leaf.

The days of buying snappers from locals showing up with one in the back of a pickup are gone, too. Bonner's are tagged, gutted, frozen and shipped from farms in Maryland and across the South.

They go into a "tea" he makes from steeping the spices and adding aromatic vegetables and a No. 5 can of tomato juice (in a 10-gallon pot). The shell stays on, adding flavor in the manner of a stewing bone or, say, chicken feet.

Later the meat - white in the shell's roof, ducklike in the carcass - is picked (and diced) by Dave Buettner with a clam fork and a powerful set of thumbs. Bonner whisks a blond roux studded with carrots, onion and celery into the broth.

And so the trilogy's hero simmers on - its aroma unashamedly musky, its texture chunky with meat, its allspice snap making you sit up and take notice in a Pineville Tavern that's shifting gears, inexorably, at tortoise speed.

Pineville Tavern

Route 413, Pineville, Pa. 215-598-3890