First issued in release COL20.12.
Last used in release COL21.5
Published in
Smith H M; Perez-Higareda G; Chiszar D. Observations on the snake genus Pliocercus, 2. The endemic species of Los Tuxtlas, Veracruz, Mexico. Bull. Maryland Herp. Soc. 32 (2): 75-79. (1996).