The horse race known as the Florida Derby in this year wearing two hats. In this one, it comes up as the $116,000 eighth race at Gulfstream Park on Monday. In that one, it will be the 116,000 ninth race, same track, some day. Ten steeds will be going for the identical boodle in ech contest.

It's divided derby, the overcrowded conditions generated by one ambitious trainer, Leroy Jolley. He now has visions of winning both halfs of the pot.

Jolley has flooded the derby's entry list with a cavalry squadron of five inmates from his 40-horse stable quartered at nearby Hialeah, forcing Gulfstream to run Monday's race in two division, rather than in one unmanageable 20-horse field.

Jolley's strong hand stems from more than numbers. His good colf, For The Movement, trained for Gerald Robins, was rated as the second or thirt-best 2-year-old last season, depending on which poll you read. For The Movement is the probable favorite in the second division of the race. The looming favorite in the first division is Nearly On Time, a colt owned by Jolley's mother.

Jolley has two other mounts going for other owner in the first division. These are Depth Finder and Solly. In the second division, as a stable companion to For The Movement, he will start Mr. Red Wing. Under Florida rules they will all be separate betting interests.

According to some trackmen, the often controversial Jolley deliverately created a split in the derby. He denies this, but otherwise refuses all discussion. "I'm not talking to anybody," he said. "I've talked enough. Now it's time to run."

To make the two divisions more attractive to the horse fan, Gulfstream has sweetened the pot by $40,000 of its own money, bringing each up to $116,000.

It's for 3-year-olds at a mile and an eighth, and is somtimes called a Kentucky Derby milestone. The race has sent four of its winners, illustrious Needles, Tim Tam, Northern Dancer and Forward Pass, on to win in Kentucky.

It will be mildly astonishing if a Kentucky Derby winner comes out of Monday's 20. Just a bit of farther south, training at the Hialeah tracks, is the unbeaten Seattle Slew everybody's choice as last year's 2-year-old champ, who is in training for his 3-year-old debut Wednesday. Seattle Slew would probably be 1-to-5 to lick anything in Gulfstream's Monday lineup, including Jolley's gang.

For The Movement has strong parental credentials as a full brother of the famd Honest Pleasure.He could face something of a contest, however, when he hooks up with Ruthie's Native in the second division.

Ruthie's Native, owned by Ruth Perlmutter, has won three of its last four, has speed, shows a liking for distance and displayed it by winning the Fountain of Youth Stakes by a runaway five lengths ahead of Fort Prevel. His owner thought it worthwhile to put up a $5,000 supplemental starting fee to get him into the race Monday.

In the weaker first division, this same Fort Prevel is a solid threat to Jolley's Nearly On Time.He has finished second in each of his last three races, including a nose defeat by Ruthie's Native. When he last hooked up with Nearly On Time he was a 1 1/2 length loser.

Monday's doubleheader is Gulfstream's farewell to the 1976-77 season before turning over the sport to Hialeah. But Gulfstream's $40,000-added investment could be a happy one, with this track's vying again with Hialeah for the important middle dates of Florida racing.

The track-versus-track dueling in Miami is always a separate feature of Florida racing. It's to Gulfstream's interest to show it can produce more betting revenue for the city, the county, and the state than Hialeah can. Monday now shapes up as a huge betting day for Gulfstream, with its twin derby feature, and for that reason nobody around here is mad at all at Leory Jolley and his troop charge.