The data presented by Kirn et al. do not demonstrate intergradation between two populations. Moreover, the diagnostic ranges of the number of subcaudals in males of hallowelli and the ratio of tail length to total length in males of gracilis do not include the recalculated means for those characteristics. Furthermore, the means for the following characteristics are dangerously close to being excluded from their respective "diagnostic" ranges: in hallowelli, the number of ventrals in males; in gracilis, the number of subcaudals in females, and the ratio of tail length to total length in females. It is incongruous that Kirn et al. state (p. 243) that "the coefficient of geographic divergence is .6 per degree latitude" for ventrals, and on the same page they state that "The average number of ventrals gradually increases toward the north in Tantilla gracilis except in southern Oklahoma and central Arkansas (the area of intergradation between T. g. gracilis and T. g. hallowelli) where the change seems to be more abrupt." The data presented in Kirn et al. (1949) do not demonstrate an abrupt change.
The present sample of T. gracilis from Kansas is clearly within the geographic range of T. g. hallowelli as mapped by Kirn et al. (1949:241). How
ever, for the sample from Kansas, the mean number of subcaudals of males is well within the diagnostic range for T. g. gracilis ([Table 6]), the mean number of subcaudals of females is closer to the mean of gracilis than it is to the mean of hallowelli ([Table 5]), and the mean of the ratio of tail length to total length of both sexes is within or very close to the diagnostic range for gracilis ([Table 6]).
Table 6. Comparison of the Means of Some Characteristics of the Sample of Tantilla gracilis from Kansas (Our Data) with Some of the Diagnostic Characteristics (Kirn et al., 1949:240) of Tantilla gracilis gracilis.
| Characteristic | Diagnostic range for T. g. gracilis | Mean of the sample ("T. g. hallowelli") from Kansas |
|---|---|---|
| No. of subcaudals males | 40-50 | 48.4 (N = 109) |
| Tail L./ Total L. females | .160-.200 | .20 (N = 79) |
| Tail L./ Total L. males | .200-.235 | .23 (N = 109) |
Smith and Sanders (1952:218) pointed out an error in the range of subcaudals in female T. g. gracilis as stated in table 1 (p. 247) of Kirn et al. We
add some additional corrections that should be made on the same page. In table two, column two ("Sex"), the words "male" and "female" are reversed for each characteristic. Also, in table two, column four ("Means from data of Force"), the means for caudals should be corrected from 33.61 to 43.61 in females and from 39.99 to 50.32 in males, as based on our recalculations from Force's data; we did not recalculate the means of Force's data for the other characteristics.