TABLE 3. Variation in Number of Supralabials Entering the Eye in 246 Specimens of Tantilla gracilis. ----------------------+-----------+------------ SUPRALABIALS | Number of | Per cent of ----------------------+ specimens | occurrence Left | Right | | ----------+-----------+-----------+------------ 3 + 4 | 3 + 4 | 233 | 94.7 4 + 5 | 3 + 4 | 4 | 1.6 4 | 3 + 4 | 1 | 0.4 3 + 4 | 4 + 5 | 5 | 2.0 3 + 4 | 4 | 1 | 0.4 3 + 4 | 3 + 4 + 5 | 1 | 0.4 3 + 4 + 5 | 3 + 4 | 1 | 0.4 ----------+-----------+-----------+------------ Dorsal scale rows Of the 245 specimens examined for this characteristic, 228 (92.7%) have scale counts of 15-15-15-15-15. The number of scale rows around the neck and one head length behind the head are 15 except in a single specimen that has 14 scale rows at these three places. The number of scale rows around midbody is 15 in 244 of 246 specimens (99.2%); two specimens have 14 scale rows around midbody. The number of preanal scale rows is more variable; counts of 14 through 17 were recorded. Fourteen specimens have 14 preanal scale rows (5.7%), 229 have 15 preanal rows (93.1%), two have 16 preanal rows (0.8%), and one has 17 preanal rows (0.4%). Known causes for atypical numbers of preanal scale rows are listed in Table 4. A preanal count at one head length anterior to the anus would have omitted most of the above variation in numbers of preanal scale rows. TABLE 4. Atypical Numbers of Preanal Scale Rows in Specimens of Tantilla gracilis.