Boris is not a Hebrew name. Bob Hall correctly translated the name as Dov Ber (Dov is Hebrew for "bear" and Ber is Yiddish for "bear." This combination of a Hebrew name and Yiddish name, both with the same meaning, is very common.)
Was Benjamin Morgolis a native of Eastern Europe? If so, he may have had identity papers that showed his name as Boris. After he immigrated, he may have gone by Benjamin.
The Hebrew inscription does, indeed, show the exact name. Benjamin's father was Abraham (or, Avraham, in Hebrew).Nonetheless, depending on the circumstances or where he lived, he also may have gone by another name closer to the national language in the country where he resided (generally, beginning with the same initial letter).