>>CK;
>>Not split but totally new and overlooked. I suspect that the new species of snake in the genus Contia could be considered as 'cryptic' in the sense that unless one is aware of how to distinguish the Forest Sharp-tailed Snake from the Common Sharp-tailed Snake (Contia tenuis), superficially they appear to be identical. That is the reason that since the late 1800's, the newly described species was overlooked by many herpetologists.
>>

Perhaps, but this species was once considered rare, and therefore not too many specimens were available in museum collections. Besides, it is not one of those glamorous species that attract the attention of both hobbyists and professionals alike. Hence it is not as well studied as large and flashy species like Lampropeltis, Elaphe and Pituophis.

>> When the sexes are treated separately, there is no overlap between the two species in two traits, relative tail length and in number of caudals. Although there is overlap in the number of ventrals between the two species, there is a very significant difference between the two species in that character as well. All other differences are more subtle. In addition, DNA testing demonstrated considerable divergence between the two species.
>>

Yes, according to the following paper, the two Contia clades diverged from each other for about 5 million years.

http://www.cnah.org/pdf_files/647.pdf

I think one scenario for their divergence may be through plate tectonics. The area occupied by the coastal Contia clade was originally in Southern California 5 million years ago. As this piece of land move north, it probably isolated these snakes from the rest of the population, and they may not have met until quite recently, just like the rubber boas of the Northwestern and Sierra Nevada subclades. In the rubber boa, the Northwestern subclade appeared to have invaded the northern Sierra Nevada. In Contia and Lampropeltis zonata, the Sierra Snakes have invaded the coastal areas.

Interestingly, both L. zonata and the coastal clade of Contia are absent from Marin County. Unlike L. zonata, however, the Santa Cruz and Mendocino Co. populations of Contia are the same, whereas the Mendocino and Santa Cruz populations of L. zonata are not.

>>Our paper will report on a third group (subspecies?) of Sharp-tailed Snake that occurs in the southern Sierra Nevada Mts. of Tulare County.
>>
>>As you are aware, the use of SVL has been a` time honored convention in herpetology. I have long held the view that such a convention is flawed in that for the most part, many herpetologists have ignored the tails of snakes as if the appendage was immaterial. I would go further by stating that it likely the Forest Sharp-tailed Snake was overlooked for so long due to the SVL convention.
>>
>>Richard F. Hoyer

SVL is useful because in many lizards and salamanders, tail autotomy is prevalent. In these species, if we measure only TL (total length) then it could be misleading since the tail may be lost or in the process of being regenerated. However, I disagree with you that herpetologists have ignored the tail, because tail lengths and the number of caudals are routinely reported in the literature. Of course, the short-tailed snake (Stilosoma) is named for its tail. Rather, I believe that the sharp-tailed snake was overlooked by many herpetologists because it was once considered rare, it was not well represented in museum collections and because it is not a glamorous species.

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