Contact of mental with chin-shields

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.

SupralabialsNumber of
specimens
Per cent of
occurrence
LeftRight
3 + 43 + 423394.7
4 + 53 + 441.6
43 + 410.4
3 + 44 + 552.0
3 + 4410.4
3 + 43 + 4 + 510.4
3 + 4 + 53 + 410.4