 The earliest known mention of a slow loris in scientific literature is from 1770 , when Dutchman Arnout Vosmaer ( 1720 – 1799 ) described a specimen of what we know today as N. bengalensis that he had received two years earlier . The French naturalist Georges @-@ Louis Leclerc , Comte de Buffon , later questioned Vosmaer 's decision to affiliate the animal with sloths , arguing that it was more closely aligned with the lorises of Ceylon ( now Sri Lanka ) and Bengal . The word " loris " was first used in 1765 by Buffon as a close equivalent to a Dutch name , <unk> . This etymology was later supported by the physician William Baird in the 1820s , who noted that the Dutch word <unk> signified " a clown " . 
