Description: Jan's Earth Snake, Adelphicos quadrivirgatus quadrivirgatus (a subspecies of the Middle American Burrowing Snake). 1 Oct 2006. Estación Biológica Los Tuxtlas, Sierra de los Tuxtlas, VER. Date: 1 October 2006, 08:07. Source: Adelphicos quadrivirgatus quadrivirgatus. Author: Cole Wolf from Albuquerque, NM, USA.