[As you can imagine, finding an X was exceedingly difficult when I was writing the “A to Z” series. (Although writing the intro was fun.) Xochimilco was one of Pomona’s longest-lived Mexican restaurants — perhaps only Tropical Mexico was older — but a few months after publication, Xochimilco expired. Its replacement, Mariscos Ensenada No. 5, is, candidly, far superior.

But a couple of generations of diners enjoyed Xochimilco and its colorful exterior mural, so this piece has value, perhaps, as history. It was published April 24, 2005.]

X marks the dining spot in ‘Pomona A to Z’

Step away from your Xbox and turn down your X record! Your full attention is needed for “Pomona A to Z,” my love letter of X’s and O’s for Pomona, as I embrace the letter X.

From Xenia, Ohio, to Xian, China, readers are wondering how yours truly, the Inland Valley’s answer to Xenophon, will find an X in Pomona.

The answer: With X-tra difficulty. To paraphrase the country song, all my X’s are in Texas, not Pomona.

Still, even if X candidates aren’t exactly springing up through xenogenesis, we can luxuriate in these runner-ups:

* X-rays at Pomona Valley Hospital Medical Center, where the radiology department handled more than 155,000 x-citing procedures in 2004.

* “X-Files,” which filmed its Jan. 13, 2002 episode, in which Agent Doggett is in a Mexican jail with amnesia, in the 500 block of West Second Street. A Virgin Mary painting done for the shoot is still visible on a brick wall.

* The businesses Xcessories N Things, Xemco Inc., Xepa Car Wash, Xiomara Beauty Salon, XLent Technology and — hold onto your hat — Xochiquetzal Dance Studio.

X-cellent! With this bounty, it must be Xmas.

Yet the X in my little xylograph is a different choice. Before you start nagging me like Socrates’ wife Xanthippe, here it is: Xochimilco Mexican Restaurant.

Opened in November 1969 and still in the same minimall at Indian Hill and Holt, Xochimilco (pronounced “ZO-chee-meel-co”) is one of Pomona’s oldest Mexican eateries.

“People used to line up 20 minutes or a half hour outside because there weren’t that many Mexican restaurants,” said waitress Elsie Alvarez, who grew up nearby.

It’s been an oasis of stability in a changing world. The name, address, recipes, much of the decor and even the phone number have stayed constant.

“Oasis” is appropriate because the real Xochimilco is a garden and series of canals outside Mexico City known as “Mexico’s own Venice.”

Restaurant founder Carroll Gauslin loved vacationing in Xochimilco, Alvarez said. But he wasn’t from Mexico.

According to the story on a past menu, Gauslin was raised in New Mexico and Texas, where he picked up a love for chiles. He created the recipes for Xochimilco himself. A friendly, well-liked man, he married one of his waitresses, Dolores.

After his death, she kept the restaurant for a spell, then sold it in October 2001 to Carlos Argueta. Since May 2004 it’s been in the hands of David Gutierrez, only the third owner in the restaurant’s 35-year history.

Xochimilco has regulars who’ve been coming for years, first with their parents and now as adults.

Cathy Goring is one of them. She e-mailed to suggest I write about the place, which she’s been frequenting pretty much since it opened. So I invited her to lunch.

“I grew up a few blocks from here. We used to come here once a month when I was growing up,” Goring told me. Those were the days when the nearby mall, now the Indoor Swap Meet, had a Sears and a Zody’s Discount Department Store.

She recalled Xochimilco’s decor as being largely the same — quirky but memorable.

Bird cages with carved birds still hang from the ceiling. (“I Know Why the Caged Fake Bird Doesn’t Sing:?) Some diners sit under a shingled covering or a trellis. Odd, but nice.

The upholstered chairs and the beautifully tiled tables are said to have been brought from Mexico by Gauslin.

But the food is key. An online dining review says that “generations have enjoyed the chile rellenos,” and Goring said they’re among her favorites too. I tried one and liked it.

“It’s always good to come back and see the food is just as good as it used to be,” Goring said of her enchilada plate. “That was my fear when it changed hands, that the recipes would change.”

One reason they didn’t is that Serafin Juarez was the cook from the beginning until just two months ago, when he retired.

The original written recipes are still used, said manager Blanca Linebaugh, who is Gutierrez’s sister.

“I have them,” Linebaugh said. “And I make sure we’re following them.”

She might go one step further and make a Xerox.

(David Allen writes Sunday, Wednesday and Friday, anxiously.)