============================================================ |Diagnostic range for | Mean of the sample CHARACTERISTIC | T. g. gracilis |("T. g. hallowelli") | | from Kansas ---------------+---------------------+---------------------- No. of | | subcaudals | 40-50 | 48.4 (N = 109) males | | | | Tail L./ | | Total L. | .160-.200 | .20 (N = 79) females | | | | Tail L./ | | Total L. | .200-.235 | .23 (N = 109) males | | ---------------+---------------------+----------------------
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.
The discussion above demonstrates that the number of subcaudals and the ratio of tail length to total length are weak characteristics for diagnosing T. g. gracilis and T. g. hallowelli. The only remaining diagnostic characteristic given by Kirn et al. (1949) is the number of ventrals. Nevertheless, a step-cline in the number of ventrals, if one exists, is yet to be demonstrated. Therefore, we completely agree with Dowling (1957:32), who stated that "... the overlap in each character is so great that any subspecific differences appear to be as yet undefined. It is here suggested that T. gracilis be retained as binomial...."
LITERATURE CITED
BAIRD, S. F. and GIRARD, C.
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BLANCHARD, F. N.
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CONANT, R.
1958. A field guide to reptiles and amphibians. Houghton Mifflin Co., Boston, 366 pp.
COPE, E. D.
1900. The crocodilians, lizards, and snakes of North America. U. S. Nat. Mus. Rept. (1898), 153-1270.
DOWLING, H. G.
1951. A proposed standard system of counting ventrals in snakes. British J. Herpetology, 1(5):97-99.
1957. A review of the amphibians and reptiles of Arkansas. Occas. Paps. Univ. Arkansas Mus., No. 3:1-51.
DUNN, E. R.
1928. A tentative key and arrangement of the American genera of Colubridae. Bull. Antivenin Inst. Amer., 2 (147):18-24.
FORCE, E. R.
1935. A local study of the opisthoglyph snake Tantilla gracilis Baird and Girard. Papers Michigan Acad. Sci., Arts and Letters, 20:645-659.
KIRN, A. J., BURGER, W. L., and SMITH, H. M.
1949. The subspecies of Tantilla gracilis. Amer. Midl. Nat., 42(1):238-251.
PETERS, J. A.
1960. The snakes of the subfamily Dipsadinae. Misc. Pubis. Mus. Zool., Univ. Michigan, No. 114:1-224.
1964. Dictionary of herpetology. Hafner Publ. Co., New York, 392 pp.
SCHMIDT, K. P. and DAVIS, D. D.
1941. Field book of snakes. G. P. Putnam's Sons, New York, 365 pp.
SMITH, H. M. and SANDERS, O.
1952. Distributional data on Texan amphibians and reptiles. Texas J. Sci., 4(2):204-219.
Morphological Variation in a Population of the Snake, Tantilla Gracilis Baird and Girard · The Wunder Library — complete classics, free to read, with narration.