By JUD COST

There are many exhibits in the hallowed halls of the California Academy of Sciences that deal with endangered species. Apparently, the Swedish pop star is not among them, judging by the massive crowd that swarmed into the sprawling museum on a chilly Thursday evening to cheer on Jens Lekman.

Those arriving when the doors opened at 6:00 p.m. could queue up for the planetarium, stroll along a circular ramp to view a rain forest or take pictures of each other in front of an over-stuffed California brown bear with a hundred-foot ichthyosaur skeleton dangling overhead. Or they could have a gander at Claude, the immense albino alligator, floating on a log while taking an early-evening siesta. Those with a more limited attention span might ogle a giant pendulum with so much mass it doesn't rotate along with the rest of the Earth and tells the time by knocking over tiny pegs.

As I walked by the hefty swinging weight, I flashed back to something almost as unsavory as the Edgar Allen Poe tale "The Pit And The Pendulum." It was the last annual freshman General Science field trip to the Morrison Planetarium by Carlmont high school, forever canceled after some of its wilder elements hopped on the swinging pendulum and rode it as if they were auditioning for Pirates Of The Caribbean.

Opening the show well before the tsunami of Lekman fans arrived, was Geoffrey O'Connor, formerly of Australian combo the Crayon Fields, singing quietly in a voice that had broken-hearted moments of Robin Gibb poking out every now and then. Once he added bass and keyboard loops to his psych-pop electric guitar, however, he ran into trouble with the bass feeding back through the PA severely enough to all but obliterate the guitar.

If you judged Jens Lekman only from his When I Said I Wanted To Be Your Dog album you might classify him as a melancholy warbler with a sound that fed directly into the tap root of Morrissey and Stephin Merritt. But Lekman seems like so much more than that tonight, very upbeat without a trace of suicidal tendencies.

Accompanied on drums and background vocals by Addison Rogers, Lekman is very chatty from the low stage constructed in the Eastern Garden, just outside the Academy's walls. Before playing "Black Cab," a low-key gem from his Oh Jens You're So Silent album, Lekman explains to the crowd that he's one of a few artists who doesn't mind if people talk during his show. "But for this one you have to be quiet-or get closer together," he says.

Lekman's best story comes from his hometown of Gothenburg, last summer. "A friend calls and says, 'Guess who just arrived in town: Kirsten Dunst.' And she supposedly really likes my songs. Now, I grew up next to a potato-chip factory, so I'm trying not to be impressed by that." But he does spend a very long time with a pal waiting for Dunst to show up in the hippest club in town. "But she couldn't get in," says Lekman. "That shows we have no VIP lists in Gothenburg." And it served as inspiration for his next song, "Waiting For Kirsten."

Some of Lekman's material recycles great moments from "Heat Wave" by Martha & the Vandellas, a vocal refrain from Manfred Mann or an early single by the Shangri-La's. But most of it is purely his own trip. And it looks like it's going to be a very long and fruitful one, at that. Just as exhilarating as Lekman's set, was the vibe of this oddball venue. I saw more beautiful girls of all ages tonight than I have in a long time. It was particularly refreshing to see the girls with the Heidi Klum legs (and dresses to match) mingling with old codgers who could have been here to accept an assignment from the National Geographic Society to search for the source of the Nile.