seven on a side (Table 1). When five infralabials are present on either one or both sides, the reduction results from one of the following conditions: a) 2 and 3 are fused (N = 3); b) 1, 2, and 3 form 1 and 2 (N = 6); c) 2, 3, and 4 form 2 and 3 (N = 3); d) 5 is separated from the edge of the lip by a projection from an adjacent infralabial (N = 1); e) 1, 2, 3, and 4 form 1, 2, and 3 (N = 2); f) type of reduction unknown (N = 4).

Of the specimens with 5-5 infralabials, two have the same type of reduction on each side, one has a different type of reduction on each side, and the type of reduction is unknown for the other two specimens.

When seven infralabials are present on either one or both sides, the addition can result from infralabials 2 and 3 forming 2, 3, and 4 (N = 2); the type of addition is unknown in one specimen.

In one specimen the second infralabial on the right side is reduced to a small wedge-shaped granule and in another specimen several infralabials on both sides are irregularly divided horizontally, although both specimens have six infralabials on the sides having the abnormalities.

Preoculars

Of the 245 specimens examined, 242 (98.8%) have one preocular on each side. Both preoculars are absent from two specimens, and one specimen has 1-0. In each case when a preocular is lacking, the "preocular" and prefrontal are fused. One specimen having 1-1 preoculars has both of them reduced to small vertical slivers.

Postoculars

Of the 245 specimens examined, 242 (98.8%) have one postocular on each side. Postoculars are 2-1 in two specimens and 1-2 in one. In one specimen the lower of the two postoculars on each side is very small, being approximately 1/6 the diameter of the upper one (measured with an ocular micrometer).

Temporals

Of the 245 specimens examined, 235 (95.9%) have 1 + 1 temporals on each side. Four specimens exhibit addition of temporals: one specimen has two secondary temporals on the left, and one has a tertiary temporal on the left. Two specimens have partly healed head injuries that probably caused atypical temporal conditions: one specimen has two primary temporals on the left, and one has two secondary temporals on the left and two upper and one lower secondary temporal on the right.

Six specimens exhibit reduction of temporals: one lacks a primary temporal on the left ("temporal" is fused with sixth supralabial), two lack secondary temporals on the right, and three lack secondary temporals on the left. The right secondary "temporal" of one specimen is separated from the supralabials by a posterior extension of the primary temporal.

Of the 246 specimens examined, 200 (81.3%) have both primary temporals in contact with their adjacent postoculars. Thirteen specimens (5.3%) have only the left primary temporal in contact with the postocular and eight (3.3%) have only the right primary temporal in contact with the postocular. Twenty-five specimens (10.2%) have both primary temporals separated from the postoculars. Separation of the primary temporal from the postocular, whenever it occurs, results from contact of mutual extensions from the adjacent parietal and supralabial (usually the fifth).

Nasal

Of the 243 specimens examined, 237 (97.5%) have the nasal divided below the naris on both sides. Three specimens have the nasal completely divided (above and below the naris) on only the left side; one specimen has a completely divided nasal on only the right side. A groove, but not a complete division of the nasal, is present above the left naris of one specimen. One specimen lacks the typical division below the naris on both sides, but a complete suture is present posterior to the naris and the resulting postnasal scales are, according to position, loreals.

Contact of prefrontal with supralabials

Of the 243 specimens examined, 147 (60.5%) have the prefrontal separated from the labials on each side. Of the remaining 96 specimens, 53 (21.8% of the 243) have the prefrontals in contact with the second labial on each side; five other variations of this characteristic were observed (Table 2).

Table 2. Variation in Contact of the Prefrontals and the Labials in 243 Specimens of Tantilla gracilis.

The specimen having the prefrontal in contact with labial 2 on the left and labial 3 on the right has seven supralabials on the right, the extra labial being added anterior to the eye. In two of the three specimens with the prefrontals in contact with labial 3 on the left and labial 2 on the right, the preoculars and prefrontals are fused on each side; the third specimen has each preocular reduced to a small vertical sliver. Of the three specimens having the prefrontals in contact with labial 2 on the left and labials 2 and 3 on the right, two are typical with respect to other characteristics that might result in this atypical condition, but one has the prefrontals and preoculars fused.

Supralabials entering orbit

Of the 246 specimens examined, 233 (94.7%) have the third and fourth supralabials entering each eye (Table 3). All snakes that have the fourth and fifth labials entering the orbit on either side also have seven supralabials on the same side. One specimen having only the fourth labial entering the eye on the right side also has six supralabials on that side, but the third supralabial is split diagonally and the part contacting the eye does not contact the lip and hence is not a supralabial. The remaining three atypical conditions (4/3 + 4; 3 + 4/3 + 4 + 5; 3 + 4 + 5/3 + 4) occur only one time each and on snakes having 6-6 supralabials.

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