The anatomy of the proboscis of the South American Tapir (Tapirus terrestris); the third figure has a horse (Equus caballus) for comparison.
Witmer, L. et al. (1999) The proboscis of tapirs (Mammalia: Perissodactyla): a case study in novel narial anatomy. J. Zool. Lond. 249, 249–267.
I recently wrote an article on the re-definition of the terms “trunk”, “proboscis” and “prorhiscis”. In short, “trunks” no longer refer to facial protrusions, “proboscides” are appendages used to eat (in elephants, tapirs), and “prorhiscides” are other big noses used for various purposes.