A highlight of American Ballet Theatre's final Wolf Trap appearance Saturday night was the company debut of the charming ballerina Alessandra Ferri, as Nikiya in "La Bayade re," Act 2, "The Kingdom of the Shades."

The Milan-born Ferri, 21, had been with England's Royal Ballet since 1980, and was seen at Wolf Trap last summer as a member of a smallish Royal touring unit, the English Ballet Ensemble. ABT announced a month ago that she would be joining the American troupe as a principal, and her debut was to be in New York at a gala "Romeo and Juliet" at the Metropolitan Opera House this coming Wednesday. A reshuffling of Wolf Trap casts this week due to dancer injuries, however, caused the company to move Ferri's bow to this area.

Ferri is petite, pretty and beautifully shaped for classical dancing, as well as an assured, artful performer of wide-ranging accomplishment and promise. As Nikiya, she demonstrated a lovely way of opening to arabesque position, like the breaking of a dawn, and velvety pirouettes. She had some moments of uncertain balance in the celebrated scarf duet, which is about par for all but the strongest and most experienced of classical technicians. Her style looked impeccable, however, and she held the stage with an aura of easy confidence.

Dramatically, there wasn't much to the portrayal, but this may well have been a chronic fault of ABT's staging. "The Kingdom of the Shades" is excerpted from a full-length Petipa ballet, and depicts the hero's opium-induced dream of a quest for his departed beloved in the spirit world. Typically, an ABT performance alludes to the dramatic overtones of this material through the winding opening entrance of the corps de ballet -- still, as this occasion beautifully demonstrated, one of the magical moments of ABT repertory -- but only fitfully thereafter. Danilo Radojevic, who was Ferri's Solor, followed the same course; he was the grieving lover on his first appearance, and a breakneck pyrotechnician thereafter. His precise, tremendous jumps and spins were indeed cause for marveling, but the drama fell by the wayside.

"Bayade re" had already been introduced Friday night as a companion for the two-act "Giselle," making for an inordinately lengthy evening. Friday's Nikiya and Solor were Susan Jaffe and Patrick Bissell, who danced reasonably well but were no more convincing expressively. The three demi-soloist Shades, in both performances, encountered the customary problems with their exceedingly difficult variations, succeeding neither less nor more than most of their many predecessors in these parts.

Marianna Tcherkassky danced exquisitely as Giselle Friday night, but the ballet as a whole still suffered from Ross Stretton's pallor as Albrecht and a general lack of romantic intensity. Carla Stallings, however, made an impressively somber, lofty Myrta. In Saturday night's "Giselle," Cynthia Harvey repeated her interestingly expressionist interpretation of the title role, with Robert La Fosse as her surprisingly deft, persuasive Albrecht.