Midbody , there are 28 – 46 dorsal scale rows , all of which are strongly keeled except for the outer rows on each side . The lateral scales are slightly oblique . The ventral scale number 124 – 140 : rarely more than 132 in males , rarely less than 132 in females . There are 17 – 33 paired subcaudal scales : males have no fewer than 25 , females no more than 23 . The anal scale is single .