The labial scales are the scales of snakes and other scaled reptiles that border the mouth opening. These do not include the median scales on the upper and lower jaws (rostral and mental scales). The term labial originates from Labium (Latin for "lip"), which refers to any lip-like structure. In snakes, there are two different types of labial scales: supralabials and sublabials. The number of these scales, and sometimes their shapes and sizes, are some of the many characteristics used to differentiate species from one another.
There are two different types of labial scales: