In snakes, the anal scale or anal plate is the scale just in front of and covering the cloacal opening. This scale can be either single ("anal entire") or paired ("anal divided"). When paired, the division is oblique.[1][2] The anal scale is preceded by the ventral scales and followed by the subcaudal scales.
^Mallow D, Ludwig D, Nilson G (2003). True Vipers: Natural History and Toxicology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. 359 pp. ISBN0-89464-877-2.
^Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates. (7th printing, 1985). 1,105 pp. (in two volumes). ISBN0-8014-0463-0.