Of the 246 specimens examined, 190 (77.2%) have the mental in contact
with both anterior chin-shields. The mental is in contact with only the
left anterior chin-shield in 15 specimens, only the right anterior
chin-shield in 2 specimens, and the mental does not contact either
anterior chin-shield in 39 specimens. Separation of the mental and an
anterior chin-shield always results from the posterior elongation of a
first infralabial.
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
----------+-----------+-----------+------------