In Virginia Beach, the post-mortem odyssey of the bottlenose dolphins usually begins with a bit of burlap and a dusting of green-tinted fly repellent.

Unless it is one of the few fresh carcasses -- those that would offer valuable information to the scientists investigating the sudden dolphin die-off -- a member of the Virginia Beach maintenance crew drags it up to the edge of the beach, away from the August crowds, unceremoniously covers it with burlap and leaves it to be retrieved by one of the Smithsonian Institution's Marine Mammal Collection's staff members.

Dead dolphins. Scores of them. For the scientists, an unprecedented mystery. For the sentimentalists, the sad passing of benign, much-beloved creatures. For the Smithsonian's Marine Mammal Collection, a windfall.

"This represents 10 years of research for us," said William McLellan, a Smithsonian field technician who has joined the team of specialists assembled in Virginia Beach. The mass mortality of dolphins has washed ashore about 200 dolphins from the coastal waters of the East Coast. In the Virginia Beach and Chesapeake Bay area, which usually produces one marine mammal stranding every couple weeks, McLellan estimates the team has retrieved 65 dolphin carcasses since the epidemic began to appear seven weeks ago.

"I'd much rather see them swimming in the water," Charles Potter, manager of the Marine Mammal Collection, said Saturday while he worked on a dolphin found on the beach at Fort Story. "But the neat thing about this, from our standpoint, is that we are getting such a cross section from the population."

Scientists, restricted to examining stranded marine mammals, have been forced to rely on data heavily skewed to the vulnerable age groups -- the very young and the very old. But this summer's epidemic has brought ashore dolphins of every age group and of both sexes, offering a rare sampling of the population.

Potter crouched over the deteriorated carcass of a small female nursling, pulled out her organs, pondered an unusual patch of crusty necrotic tissue in her abdominal cavity, dropped pieces of tissue into little plastic bags and, finally, placed the head in a thick garbage bag, tied it, tagged it and loaded it into a truck.

To lovers of the playful bottlenose, such an end may border on the gruesome. But to the scientist, this is routine data collecting: a Smithsonian field number, measurements and "vital statistics" recorded on a Cetacean Data Record, a no-frills necropsy -- the animal equivalent of an autopsy -- and a quick decapitation. And eventually, for the scientifically useful pieces -- the skull, the flipper, the stomach contents, its parasites and its sex organs -- a place in the collection and research projects of the Smithsonian's marine mammal program at the National Museum of Natural History.

As the deaths continue, drum-shaped Liqui-Paks filled with dolphin parts will arrive by the truckful at the loading dock of the museum building. They will be stashed in the back of a walk-in freezer, along with the heads of baby whales and other tissue samples. When time permits, they will be thawed and examined.

Flippers will be radiographed. Perhaps an unusual specimen -- some middle ear tissue that is filled with parasites, for example -- will be dropped into a bottle of alcohol and stored on a shelf in the Alcohol Room on the third floor of the museum. Skulls and other skeletal parts will spend two or three weeks in the Beetle Room, where the larvae of carpet beetles will clean the bones with such voracious thoroughness that the only trace of soft tissue to remain from the dolphin will be a coarse powder that looks like lumpy sawdust.

Finally, its skull will have a place in a cabinet in the museum's basement, the Small Marine Mammal Osteology Collection.

"For years and years, we have been banking away data on the bottlenose dolphin," said James Mead, curator of marine mammals at the Smithsonian. "We are interested in getting the basic natural history data on dolphins: What they eat, their stomach contents, when they become sexually mature, when they become physically mature, their patterns of movement, are the animals at Virginia Beach one school that comes in and stays there, or do they occupy the vanguard of a migrating population and the animals you see off Virginia Beach are different every week -- part of a migratory strain?"

To a large extent, to study the natural history of cetaceans, the scientific order that includes whales and dolphins, is to be an ambulance chaser.

Because of the Marine Mammal Protection Act of 1972, the scientists are limited to what nature gives them -- to what washes up on shore. "If you are going to look sideways at a cetacean," Mead said, "you have to have a federal permit."

Thus, the Smithsonian's Marine Mammal Stranding Center, authorized by the National Marine Fisheries Service, enables scientists to respond to the strandings in the Chesapeake Bay, Virginia Beach and South Carolina area to minister to the sick ones and to retrieve the dead ones for their research.

"We are going about compiling the biological information of cetaceans in the same way that an alien life form might compile the natural history of humans if he were restricted to information that was derived from the county coroner's office," Mead said.

The Marine Mammal Collection of the Smithsonian has "the largest collection of cetaceans in the world by a factor of three or four," Mead said.

The Smithsonian has specimens of all but six of the 75 species within the cetacean order. The ubiquitous bottlenose dolphin -- known to marine mammalogists as tursiops truncatus -- is not one of those six species: The collection has 524 tursiops specimens on record and many more on the way.