Information on both Jonas and Mykolas Pez^a can be found in Volume 2 of the book Lithuanian Religious Life in America by the late Father William Wolkovich-Valkavicius.
Page 481 of Volume 2 lists Father Tomas Z^ilinskas as a cousin on Jonas.
Jonas is listed as "Jonas Z^ilinskas (later Z^ilius; in some church records signed himself as Zillinsky." He was born 18 October 1870 in Domeikai village, Sunskai homestead, county of Marijampole. His studies at the Plock seminary were financed by his uncle, Father Mykolas Pez^a. He was ordained in 1892 in the U.S. Jonas was pastor at Holy Cross Church in Mount Carmel, Pennsylvania where he succeeded his uncle, Father Mykolas Pez^a.
Father Mykolas is listed as returning to Lithuania in 1920.