May 18, 1982

jawed tommy-goff (a highly poisonous snake also known as the fer-de-lance). In the area as well are coral snakes, jaguars and crocodiles. None of the archeologists at work here has been bitten by anything more fierce than a mosquito (although they are particularly fierce in this neighborhood), but every now and then a local child falls victim to a crocodile. In the words of Richard MacNeish, who leads the effort based at a camp near here, Belize now is ''wall-to-wall archeologists'' because of the difficulties of working in Mexico or elsewhere in Central America. Guatemala and El Salvador are beset by guerrilla warfare. Mexico, according to archeologists here, will only authorize research by outsiders if they turn over 15 percent of their grants to the Government.

The United States and other major industrial countries are near a new monetary agreement that would stabilize the dollar's value in currency markets and provide for tighter coordination of economic policies, officials close to the negotiations said today. These countries hope to complete the pact at the economic summit meeting that starts at Versailles June 4. The meeting will be attended by President Reagan, President Francois Mitterrand of France, Chancellor Helmut Schmidt of West Germany and the Prime Ministers of Belgium, Britain, Canada, Italy and Japan. The essence of the emerging accord, the officials said, is a bargain between the United States and the seven other countries attending the Versailles talks.

IN a six-foot-tall cage at the American Museum of Natural History, a starling flits from perch to perch, casts a quick glance at a visitor and says, ''Hi Sam! Hi kid!'' Not quite Bogart, but very human. The abilities of this bird and of some of its cousins, to imitate human speech - indeed, to mimic a great variety of other sounds with uncanny precision - is now the focus of attention for biologists and ornithologists in many parts of the world. How is it, they want to know, that these creatures, in captivity and in the wild, can accomplish such virtuosity in sound with a primitive vocal apparatus and a brain about the size of a grape? What is it that enables some kinds of birds, in particular the starling family, Sturnidae, of which the myna is the most famously talkative, to learn to speak more than 50 words in some cases and utter as many as 20 sentences? Listeners to a captive starling in Falmouth, Mass., report, for example, that not only can it whistle ''Michael Row the Boat Ashore'' and the opening bars of Beethoven's Fifth Symphony, but it also ''talks'' on and on, saying such things as: ''I go home - you go to sleep. He's a little, bitty baby boy. Yes he is! See ya later. Bye-bye!''

Westchester County, where flooding from swollen rivers and streams is a common occurrence, signed an agreement with the National Weather Service today for an electronically operated flood-alert system. It is scheduled to be put in operation this fall. Officials said it would be the first ''automated early flood warning system'' in the Northeast, and similar to systems in California, Arizona, Oregon and Tennessee. Executive Alfred B. DelBello said two years of planning for ''critical advance notice'' to local communities preceded today's announcement.

Argentina's Finance Minister, Roberto Alemann, said yesterday that he had received assurances from bankers in the United States and other countries that they would continue to roll over Argentina's short-term debt until the Falkland Islands dispute is over. Banking sources said they would go along with the Argentine request because, as one leading banker put it, ''there's no other way.'' Interviewed by telephone in New York, before he returned home after a trip that included stops in Helsinki, Paris and Zurich, Mr. Alemann said that $700 million of debt had already been paid off this year and that payments were being made as they came due. Argentina's total debt was estimated at $35.7 billion at the end of 1981, including $9.2 billion owed to American banks.

In a major Arab entry into Western European industry, Kuwait has acquired roughly 25 percent of Hoechst, the West German chemical giant, West German banking officials disclosed today. Based on Hoechst share prices in recent months, the quoted value of the purchase is estimated at $609 million.The banking officials, who asked that their names not be used, said that Kuwait had purchased the Hoechst shares piecemeal over an extended period of time. The gradual acquisitions, they said, enabled Kuwait to skirt West German securities laws. German law stipulates that if a purchaser buys a block of stock equal to more than 25 percent of a company's total equity, the transaction must be registered with securities officials and be approved by the federal antitrust agency.

International The Common Market extended its sanctions against Argentina for one week in retaliation for its seizure of the Falkland Islands. The vote, however, was not unanimous. Italy and Ireland disassociated themselves from the ban, but a spokesman for the Irish Government said that Ireland would use its own means to prevent Argentine imports during the coming week. (Page A1, Column 6.) U.N. talks on the Falklands resumed after a two-day break. Sir Anthony Parsons, the British delegate, said he had returned from London ''with instructions to continue the negotiations.'' Remarks by the Argentine envoy, Enrique Ros, were interpreted by diplomats as an indication that he had perceived a shift in Britain's stance. (A1:5.)

IN February 1980 the faculty of Villanova University outside Philadelphia was preparing to vote on whether to form a union. Ten days before the scheduled election, however, the United States Supreme Court ruled that faculty members at Yeshiva University in New York City were not eligible to engage in collective bargaining because they were ''managerial.'' Citing the Yeshiva ruling, the Villanova administration successfully petitioned the regional office of the National Labor Relations Board to cancel the election, effectively putting a stop to organizing at that insitution. ''That was it,'' said Joel M. Douglas, director of the National Center for the Study of Collective Bargaining in Higher Education at Baruch College. ''No bargaining. No talk. No nothing.''

The stock market dropped sharply amid growing concern over persistent high interest rates and the condition of the economy. The Dow Jones industrial average closed down 12.46 points, to 845.32. The decline was the biggest since Feb. 22, when the Dow fell 13.04 points. In the last six sessions, it has tumbled almost 24 points. (Page D1.) Interest rates rose modestly as dealers cut prices because of concern about the continued high cost of financing inventories. (D9.) The dollar rose against most major currencies, while gold prices fell $4 an ounce, to $334, in New York. (D14.) Heating oil futures prices eased amid profit taking after last week's surge. (D14.)

A divided Common Market agreed Monday night to extend for one week the sanctions imposed against Argentina a month ago in retaliation for its seizure of the Falkland Islands. Italy and Ireland disassociated themselves from the extension of the sanctions, which included a total ban on imports from Argentina. These totaled $1.8 billion in 1980. A spokesman for the Irish Government said his country would use its own means to bar Argentine goods in the next week.

Negotiations designed to end the fighting over the Falkland Islands resumed here today after a two-day break with some indications of more flexibility in the British position. Tonight, however, Secretary General Javier Perez de Cuellar left United Nations headquarters saying: ''I am more than ever convinced that time is not on the side of peace. The next few days will be decisive.'' Sir Anthony Parsons, the British delegate to the United Nations, said he had returned from London ''with instructions to continue the negotiations.'' He gave no public hint whether Britain's posture had changed.

THE loss of sexual potency, long thought to be an emotional problem in nearly all cases, is now often found to be brought on by physical conditions. And major advances are being reported in successfully treating impotence caused by these conditions and by emotional factors. Recent improvements in diagnostic techniques have revealed that a variety of organic factors, including nerve and blood-vessel diseases and hormonal abnormalities, are the underlying cause in perhaps a third or more of the estimated 10 million impotent men in this country, experts say, though emotional factors may also compound the problem. Dr. Richard Green said in an interview: ''With advances in diagnostic techniques, which include vascular, X-ray, endocrine and sleep-lab studies as well as improvements in taking a history of the sexual problem, more cases once thought to be purely psychogenic are now known to be organic or a combination of psychogenic and organic issues.'' Dr. Green, a psychiatrist at the State University of New York at Stony Brook, is co-author with Dr. Gorm Wagner of ''Impotence,'' a comprehensive text recently published by Plenum Press.