skull cap, 無沿便帽

A woman holds a baby wearing a white skull cap, at the end of Pope Francis' weekly general audience, in St. Peter's Square, at the Vatican.
September 30, 2015
http://www.voanews.com/media/photogallery/september-30-2015-day-in-photos/2985941.html

skullcap汉语(繁体)翻译：剑桥词典 - Cambridge Dictionary

（尤指猶太教徒或天主教高級教士所戴的）無沿便帽