Composer: Saint-Saëns, Camille (1835-1921)
Work title: The Swan (Le Cygne), from Le carnaval des animaux (1886)
Type of composition: Piece
Movements/sections: 1
Number of pages: 2 + 3 (Score + Parts)
Arrangement: Viola Duet 

There's a Violin Duet here too. This piece is also part of The Carnival of the Animals Suite for Two Violas

Video of the Violin Duet: