April 21] 1861, Zhitomir, Russian Empire – August 14, 1927, Dudergof, now Mozhaisky, Soviet Union) was a Russian and Soviet ethnographer of Jewish origin who from 1889 to 1897 studied the Nivkhs (Gilyaks), Oroks, and Ainu on Sakhalin and in Siberia for the American Museum of Natural History, in New York City.