"Diamondback and canvasback" as the game dinner in the salad days of H. L. Mencken. A soup course of diamondback terrapin followed by canvasback duck graced the tables of Baltimore burghers,rs, Philadelphia lawyers, New York nabobs and other persons of quality as far inland as Chicago.

Generations of Eastern Shore watermen fished and gunned by fair means or foul to supply the demands of restaurants such as Delmonico's of New York, where the nouveaux riches of the Gilded Age staged orgies of conspicuous consumption. Well past the turn of the century thousands of barrels of terrapins and waterfowl sped north and west, often in special express trains, at ever-rising prices that reflected the dwindling of the slaughtered wildlife of the Chesapeake. Sixty years ago, choice terrapins were selling for more than $100 a dozen, more than a month's wages for most workers.

Like many another American excess, game-gorging faded out as the Roaring Twenties collapsed into the Great Depression. The conservation movement and game laws are credited with having saved the beasts and birds from extinction, but the son of one of the first Chesapeakee game wardens has a different explanation:

"The market gunners were fierce old boys, and they laughed at the idea of protected species and bag limits," he said. "The feww who still are living still are poaching, their arthritis permitting. What saved the birds, especially, was their scarcity. It got to the point where it wasn't any use to go out with a lantern and punt gun because there just weren't any great rafts of birds left to shoot."

Be that as it may, most of the birds and beasts are back, many in even greater abundance than in the bad old days, and the present generation can feast as well, if not perhaps as piggishly, as J. P. Morgan or Diamond Jim Brady ever did.

Better, in fact, because the modern gourmet can -- must, practically -- go into the field and the marsh to gather his own game. To the pleasure of fine eating he's almost forced to add the pleasures of a week or a season of getting tired, cold, wet and dirty and so, for a change, earning what he eats.

The ultimate Chesapeake game feast is a four-course affair, to which can be added a dessert course of choice (it would be hard to improve on Port or Madeira with nuts, fruits and cheeses): Oysters and/or clams on the halfshell Terrapin soup or stew Duck, goose and/or marsh hen Venison Anyone who undertakes to serve such a feast should take special care with the fowl and venison courses, because terrapin is a tough act to follow. The pungent aroma and deep, rich flavor are like nothing else on earth, and current generations are to be pitied for never having tasted it.

There are two legal complications:

The diamondback terrapin, although abundant throughout Maryland's salt marshes, is totally protected in that state. The prohibition began when the species was endangered but continues because the terrapin has become a state symbol, according to one state wildlife official. Not to worry, since the diamondback ranges the coasts of 14 other states from Massachusetts to Texas. The exquisitely figured and delicately colored terrapin particularly abounds in the marshes of Virginia's Eastern Shore, where thousands may be seen sunning themselves along a single mile of creekbank and hundreds may be landed in one haul of a net. One authority called them "common as pig tracks."

The canvasback, although no longer endangered, is locally "stressed" and therefore protected in most parts of the mid-Atlantic states. But it's no loss to the palate to substitute other waterfowl.

Any hunter can be presumed to know how to supply the fowl and venison courses, but terrapin fishing is on the verge of becoming a lost art. As far as I know the only man still taking them commercially is Carlton (Cork) McGee of Chincoteague, who fills occasional special orders. The odd terrapins that stray into his fishing nets go onto his own table, in pot pies or stews.

The warm-weather method of fishing terrapins is to set a net across a "creek," or marsh channel, on a falling tide, when they head out to feed in deeper waters. In some shallows they can be dipped up with blind stabs of a hand net, so thick are they. But cold weather is really the season, according to The Epicurean, a 1920 tome by Delmonico's chef Charles Ranhofer:

The time for hibernation begins with approaching frosty weather and continues till the warm spring; they bury a few inches deep in the mud and leave, at the spot where they disappear, a mound in the middle of which a hole can be discerned. They are at their best from December to March.

The favorite place for the hibernation of the very largest size is a few inches below the soft oozy mud [in the beds of] the thousands of creeks that penetrate the shores and islands of the Chesapeake. Those less frequented by man are instinctively selected by the terrapin for its haunts.

It frequently requires many days of laborious and tedious work and many miles of walking over soft boggy marshes, of prodding in narrow channels with long shafted tongs before one is taken from a hiding place, just below the surface, sufficiently deep for protection against frost .

These being the good new days, the terrapin is a deal easier to find, but it still involves a lot of slogging through the marsh. If the terrapin seeker takes along a shotgun he is likely to bag the bird course of our ideal game dinner at the same time, because the trekker in the marsh will see waterfowl in numbers unsuspected by gunners who like to keep their feet dry. TERRAPINING

Be there at low tide, and if you can't find oyster tongs, use a long-handled garden rake. A gunnysack is all that is needed to keep the beasts from crawling around in the boat. Look for the telltale holes at the water's edge and probe bottoms not carpeted by oysters and clams (after you've raked up all the shellfish you want). Use the tool to test the depth before crossing side channels; even on a mild day a wetting can lead to hypothermia in short order.

There is no standard for a "keeper" terrapin. A male of any size identifiable by the dark plastron, or undershell, is fair game, although they are uniformly small. A full-grown one is about the size of a skinny box turtle, and a mess of them can be a trial to clean. By ancient custom terrapins are measured by the length of the plastron, and a female under five inches ought to be left to mature and reproduce her kind. Mature females always contain egg yolks, an important ingredient in the soup or stew.

Several hundred females caught off Chincoteague this year averaged about six inches and two to three pounds. If you come across a bunch of big ones, don't be shy about filling a couple of sacks; the meat, eggs and liver freeze very well.

Traditionalists insist on fresh terrapin, and the animals are quite easy to handle and keep. They will stay live and well for weeks or months in a tub of water in a cool, dark place. The water should be shallow enough for them to breathe without having to swim, and the tub should be covered with a board to keep them from climbing out. They are not in the least vicious, for all their mean-looking jaws, but it can be disconcerting to find them crawling around the basement. The water-should be changed daily for the first week, after which the turtles' instestinal tracts will be empty of sand and shell fragments.