MADRID — Catalans may still be weighing whether to quit Spain, but Catalan cities with Jewish histories have already made up their minds. Quietly, last month, they decided to withdraw from a Spanish network of cities with historic Jewish medieval quarters.

The planned exit of five Catalan cities, which account for one-fifth of the network of Jewish quarters, will also force the network to appoint a new leadership, as both its president and secretary general were Catalans.

Marta Madrenas, the mayor of Girona, one of the Catalan cities that has decided to leave, said in an interview that she and her colleagues would instead create their own Catalan network soon because “we think we can do better in terms of showcasing our Jewish patrimony.”

“We want to do it in a more serious manner, with more cultural and scientific rigor,” she said.

Girona, she noted, has already set up a center of Jewish studies. A new Catalan network, she said, can put an emphasis on introducing “more conferences, debates, as well as developing student scholarships — it must be about culture and can’t be all about tourism and tour operators.”