Interior Secretary Cecil D. Andrus is facing mounting congressional pressure to reverse a decision to fire a highly raised endangered species scientist who last week wrote to one of Andrus' favorite French restaurants on official stationery to that rattlesnake meat be taken off the menu.

Several members of Congress said yesterday that they have put Andrus on notice: either reinstate herpetologist C. Kenneth Dodd forthwith, or face the prospect of congressional scrutiny of the situation.

Indeed, the firing of Dodd, 29, has brought politicians leaping into the ring on the side of the apparent underdog, a $21,000-a-year scientist who asked Dominique's restaurant to remove the threatened Pennsylvania timber rattler from the menu. At the time, it was bing sauteed and served with string beans and red cabbage at $9.25 a plate.

"Offending the owner of your boss' favorite restaurant is hardly cause for dismissing a civil servant," said Rep. Patricia Shroeder (D-colo), chairwoman of the House civil service subcommittee. She went on to assert yesterday that Dodd's firing was "a corruption of the whole [civil service] system," and threatened to call Andrus on the congressional carpet for possible violations of the Civil Service Reform Act. "If he doesn't back off, we certainly will hold hearings," she said "It's a terrible precedent to allow. I'm overwhelmed that he thinks he can get away with this."

The firing of Dodd -- for what he concedes may have been an overzealous act on his part -- couldn't come at a worse time for environmentalists, say several Hill staffers. The House is expected to vote on reauthorizing the Endangered Species Act of 1978 next week, and Dodd's firing -- even if it was over the unloved rattlesnake -- raises questions about Andrus' dedication to the act's provisions, as its chief steward, they say.

"Mr. Andrus' behavior raises substantial questions about the responsible administration of the statute," said the act's congressional author, combative congressman John Dingell, (D-Mich.), who has fired off a letter to the Interior secretary demanding a full explanation of Dodd's dismissal. "It smacks of the highest and most outrageous arrogance."

Dingell said he was rebuffed by Interior Department staff members yesterday when he asked to have Endangered Species Program Director Hal O'Conner answer a few questions regarding Dodd's firing -- on grounds that privacy status could be violated. But the congressman, a noted sportsman and National Rifle Association board member who once stopped a charging wild boar with a .44-caliber handgun, vowed he would secure a full explanation.

"Andrus ain't going to stone-wall it," Dingeli said. "We'll have him produce the information, even if we have to make a Freedom of Information request." Otherwise, he said, "there'll be blood and guts, hair and hide all over the wall."

Interior spokesman Alan Levitt said Andrus would have no comment "They're going to have to wait and see what happens with Dodd's appeal [to assistant secretary Robert Herbst]" he said "Assistant secretary Herbst will treat his appeal fairly.

Dingell has also asked Rep. John Breaux (D-La), chairman of the subcommittee on fisheries and wildlife, of which Dingell is a senior member, to investigate the incident. Breaux is "seriously considering" the request, Dingell said.

Dodd is appealing the firing notice he received last Thursday and has 30 days before it takes effect. He must file an appeal by Oct. 26 with assistant Secretary Herbst, who will decide whether to reverse the decision, or let it stand.

"We're holding off calling the hearings, in the hopes Andrus finds a face-saving way out of this," said Andrew Feinstein, Shroeder's civil service subcommittee staff director.