[1] His most significant work was Histoire Naturelle des Araignées (1892–1903), an encyclopedic treatment of the spider genera of the world.

[1] The International Society of Arachnology offers a Simon Award recognising lifetime achievement.

[3] The Eocene fossil spider species Cenotextricella simoni was named in his honor.

Simon made the first collections of birds in the Sierra Nevada de Santa Marta region of Colombia.

[5] During his career, described several species and races as well as creating the genera Anopetia, Stephanoxis, Haplophaedia and Taphrolesbia.