My maternal grandmother, Zofiz Serednicka, came from Ulucz and her father's name was Nykolaj Serednicky (born 1854). Her mother was Anna Dziubakiewicz. Zofia also had brothers Theodor and Michael Serednicky who emigrateed to the United States before WW I, but I have no knowledge of any other siblings who remained in Ulucz. I do know that she visited her "family" in Ulucz in 1932 before WW II, so she had good reason to go back there. Feel free to contact me. We may have some family in common. Attached is a picture of Nykolaj which my grandmother brought with her to the US.