November 2, 1982

JENNY O'BRIEN and Ben Cotton attend a preparatory school, yet they are hardly typical preppies. Neither has any intention of applying to Yale, Harvard or Princeton. Their goal is to enter the United States Military Academy at West Point. Like their classmates at the Military Academy Preparatory School at Fort Monmouth, N.J., they wear Army fatiques to class rather than the Brooks Brothers shirts de rigueur at other exclusive schools. Applications for admission to the military academies have risen steadily in the last few years, giving the Fort Monmouth school, along with the Naval Academy Preparatory School in Newport, R.I., and the Air Force Preparatory School in Colorado Springs, all quasimilitary institutions operated by the Defense Department, an increasingly important role in preparing the nation's future military leaders.

The professional politicians will be watching the early returns in Indiana, Maine, Rhode Island, New Jersey and Virginia tonight, seeking the first clues on how the Democrats are doing in their efforts to win the mid-term election. Those states will provide the initial indications of whether Democrats are benefiting from either an unusually small or an unusually large turnout; whether the Republican base vote is active, disaffected or staying home; whether blacks are coming out in force to protest Reagan Republicanism, or whether Republicans are the ones showing surprising strength. Even before the polls close, the political experts will have diagnosed the weather. Good weather in California, central Illinois, Florida or Delaware could help Democrats increase their turnout. The three major television networks will have conducted surveys with voters leaving the ballot booths to help project trends and winners in important battlegrounds like New York, New Jersey, Texas and California.

million-year-old grave in South Africa, had belonged to an animal the size of a ferret, about a foot long. This was one species, Thrinaxodon liorhinus, of the therapsids that dominated terrestrial life for millions of years before the rise of dinosaurs. Not only did the dinosaurs overwhelm the therapsids in nature's continuing war of survival, driving them to extinction, but they also have overshadowed them in the minds of humans who essay to reconstruct this distant past. The neglect is undeserved. For just before their kind vanished, some therapsids made the fateful transition from reptiles to the first mammals. They were the ancestors of every bat and cat, whale and primate, every human being. There in the little Thrinaxodon jaw, Dr. Crompton pointed out, was one of the more telling clues to the evolutionary trend that would be the therapsids' destiny. The teeth-bearing bone, the dentary, was clearly developing a nonreptilian size and shape. Other jaw bones were already shifting toward their future places in the mammalian middle ear.

A list of candidates in Metropolitan Report yesterday incorrectly identified one contender in the 84th Assembly District. He is J. Henry Neale Jr., running on the Democrtic and Liberal lines.

French-Manitobans win their case A2 Soviet bars pacificist group from holding news conference A3 Attorney General Smith ''heart- ened'' by visit to Thailand A4 Around the World A5 U.S. backing raids on Nicaraguan border A6 Three members of hospital staff testify before massacre panel A13 Government/Politics Cuomo appeals to his supporters to get out the vote B1 City must answer charges by striking Legal Aid lawyers B3 Senate candidates in Jersey seek votes of independents B4 Challengers in Connecticut contests continue campaigning B4 Reagan shows concern on Social Security as election issue D22 ELECTION DAY Poll hours - New York, 6 A.M. to 9 P.M.; New Jersey, 7 A.M. to 8 P.M.; Connecticut, 6 A.M. to 8 P.M. Parking - Alternate-side rules suspended. Sanitation - No collections; no street cleaning. Stock and commodity markets, and banks - Some open, some closed; see page D2. HO Federal offices - Open. State and municipal offices - New York and New Jersey, closed; Connecticut, open. Post offices - Regular operations. Transportation - Subways, buses, Long Island Rail Road and Conrail on regular weekday schedules. Libraries - Closed. Schools - New York, closed; New Jersey and Connecticut, closings vary.