_Tantilla_ reportedly has two nasals (Baird and Girard, 1853:131; Cope, 1900:1110; Wright and Wright, 1957:722). _Tantilla gracilis_ usually has a single nasal that is divided below the naris; variation in this characteristic is discussed above. In addition to the generic characteristics, specific characteristics for _T. gracilis_ are as follows: supralabials 5-8 (usually 6); supralabials 3 and 4 entering orbit; infralabials 5-7 (usually 6); temporals 1 + 1; ventrals 115-138 in females, 106-132 in males; subcaudals 33-53 in females, 40-57 in males; tail length 13-27 per cent total length in females, 15-30 per cent in males (Baird and Girard, 1853:132; Cope, 1900:1111-12; Force, 1935:653-54; Taylor, 1936:337-38; Blanchard, 1938:371-72; Kirn, Burger, and Smith, 1949:240-49). Excepting the number of temporals and the supralabials entering the orbit, the characteristics of the specimens in our sample are within the ranges of variation mentioned above. Of the 10 maxillary characteristics studied, no variation was observed in number of fangs or angle of lateral flange. Because our data have some bearing on the problem of geographic variation in _T. gracilis_ and the recognition of subspecies, we comment briefly on the status of subspecies in _T. gracilis_. Kirn, Burger and Smith (1949) proposed the recognition of two subspecies of _Tantilla gracilis_ (_T. g. gracilis_ Baird and Girard and _T. g. hallowelli_ Cope). These subspecies were diagnosed on the basis of differences in ventrals, subcaudals, and the ratio of tail length to total length; sexual dimorphism in each characteristic was considered. We do not recognize these subspecies for the reasons given below. The data of Kirn _et al._ (1949) appear to be presented inaccurately in part. Both of us independently recalculated the mean given for each characteristic for each subspecies, using the data in figures 2-4 of Kirn _et al._ (1949:242, 244-245). Of their 12 means presented (table 1, p. 247) only two agree with our recalculated means, although the means calculated by each of us independently are in complete agreement (Table 5). Also, we independently calculated the percentages of specimens of each "subspecies" that are included in the ranges of variation given in their diagnoses (Table 5); again, our independent calculations are in complete agreement. In our opinion the differences between the populations for the characteristics analyzed do not warrant recognition of subspecies (Fig. 6). TABLE 5. Means of "Diagnostic" Characteristics of T. g. gracilis Baird and Girard and T. g. hallowelli Cope.