There were no mummified bodies or caged teenage girls in Harrison G. Dyar’s tunnels. His tunnels were not the site of satanic rituals or drunken orgies. He did not use the tunnels to escape from his wife or to hide treasures pilfered from the Smithsonian. He was not trying to find Atlantis. He did not think he was a termite.

Harrison Dyar said he excavated tons of earth underneath his Washington houses as a way of getting exercise. I believe him. I think he just liked to dig. And I think he took great pride in his construction skills. Is that any stranger than a man who fills his basement with model trains?

Yes, of course it is. It’s weird. And it’s weird because we associate the gloom and claustrophobia of a catacomb with unknowable mysteries. The subterranean illustrates the subconscious, a manifestation of all those urges we can’t control.

And Harrison Dyar had urges. For years he carried on a love affair with unwed kindergarten teacher Wellesca Pollock. He fathered children out of wedlock and went so far as to concoct a fictitious husband for Wellesca. The tunnels may have been the least odd thing about him.

Some believe Dyar dug the passages so he could sneak between his families. Not true. His two houses were miles apart. While it’s conceivable Dyar had assignations with Wellesca in the tunnels he built under his home on 21st Street NW — there were at least two entrances — I doubt it. His son Otis used to play in them. Dyar couldn’t have risked discovery.

Marc Epstein, an entomologist who is working on a biography of Harrison G. Dyar poses with a chameleon while on a moth survey in Kenya on September 13, 2010. (Todd M. Gilligan/TODD M. GILLIGAN)

But the main argument against the tunnels being used to reach Wellesca is this: Dyar dug another set under the B Street home he shared with her.

This isn’t to suggest that the tunnels were just tunnels, the way a cigar is sometimes just a cigar. I see the tunnels as the physical manifestation of Dyar’s duality: analytical on the surface, passionate underneath. What interests me as much as his nocturnal excavations is this: Did Dyar ever feel guilty about the lies and the subterfuge?

I think the answer can be found in the Latin carved on an arch in the B Street catacomb: Facilis descensus Averno. From “The Aeneid,” it means, “The way down to Hell is easy.” But Virgil’s passage continues: “The path out of Hell is hard.” Maybe Dyar chose that line because he knew he was a sinner, unable to resist his urges.

Odd as Dyar might have been, he was a master entomologist, describing about 3,000 new species of butterflies and moths and 600 of mosquitoes, either by himself or with collaborators. His colleagues named nearly 70 insect species after him, from the mosquito Dixa dyari to the moth Euleucophaeus dyari.

Marc Epstein probably knows Dyar better than anyone. He is himself an entomologist who worked at the Smithsonian, an expert on limacodid moths, one of the moth families Dyar was most passionate about. Today, Marc is an entomologist for the state of California, and over the past 20 years he has been working in his spare time on a detailed biography of Dyar.

“His story is pretty widely circulated in entomology,” Marc said. “He really laid down some amazing big-picture stuff on what we call phylogeny.” That’s the study of how organisms are related, much like a genealogy, but based on evolutionary theory.

At a time when most taxonomists ignored larvae, “He looked at the whole organism, as opposed to just the adult stage,” Marc said. Dyar is best known for formulating Dyar’s Law, an equation that allows entomologists to estimate a larval insect’s stage of development based on measurements of its head.

Dafydd Dyar, a technical consultant and writer who lives in Oregon, is the son of Harrison and Wellesca’s oldest son, Roshan. Dafydd never met his grandfather, but he recognizes in him the family’s anti-authoritarian streak.

“We do have a can-do, never-say-die, authorities-be-damned attitude,” Dafydd said. He said of his grandparents, “If society didn’t approve, well, they didn’t have to know.”

And what of the tunnels themselves? After Dyar’s death, the Department of Agriculture bought the B Street house to use its dark, moist passages for mushroom-growing experiments. The tunnels were briefly considered for use as air raid shelters during World War II. Everything was demolished in the construction of the FAA headquarters.

As for Dyar’s 21st Street tunnels, an entrance was exposed in 1958 when Lewis Curd was building a wall behind 1510 and 1512 21st St. NW. His three children were hustled underground for a photo that ran in this paper.

“What I saw of it was well built,” said Chip Curd, now 60 and a Virginia pediatrician. His family still owns the two houses, which are divided into rental units. “I’m probably the only one who remembers it.”

Today, a concrete slab blocks the entrance to the tunnels — or the former tunnels. Chip is certain that construction over the past 100 years has caused whatever is left of Dyar’s catacombs to collapse.

But who knows what other strange Washington stories sit buried, just waiting for a little bit of sunlight, just waiting for their day of discovery?

I consulted many sources while researching Harrison G. Dyar. Thank you to Marc E. Epstein, who, with the Smithsonian’s Pamela M. Henson, published the fullest account so far of Dyar’s life in a 1992 edition of American Entomologist, the magazine of the Entomological Society of America. What we know about Dyar today is due to Marc’s tireless effort.

I also appreciate the assistance of the staff at the Smithsonian Institution Archives, Shenandoah National Park (especially Reed Engle, the park’s former historian), the Library of Congress, the National Archives, the Bahai National Center, the National Museum of Natural History, D.C. Public Library’s Washingtoniana Division, the Historical Society of Washington’s Kiplinger Library, Marilyn Arnold of Find Your Family, Brian Kraft (compiler of historic District building permits), the District Department of Transportation, DC Water and Dafydd Dyar.