Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae) Author Hedges, Blair Author Couloux, Arnaud Author Vidal, Nicolas text Zootaxa 2009 2067 1 28 journal article 10.5281/zenodo.187018 35d81ccb-1856-4852-a5b6-d9058b3dbc0b 1175-5326 187018 Genus Arrhyton Günther, 1858 Type species. Arrhyton taeniatum Günther, 1858 :244 . Diagnosis. See diagnosis for the subtribe Arrhytonina. Content. Eight species are included in the genus ( Table 1 ). Distribution. The genus is distributed throughout Cuba ( Fig. 2 ). Remarks. Species of Arrhyton ( Fig. 3 G) are small ( 448 mm , maximum SVL) racers. An informal classification of Cuban Arrhyton was based on color pattern and scalation, especially ventral and subcaudal counts ( Schwartz & Garrido 1981 ; Hedges & Garrido 1992 ). The most distinct species, morphologically, is A. taeniatum , because it lacks a loreal scale, has an enlarged rostral (presumably related to semi-fossorial habits), and has a boldly striped pattern. It was placed in its own species group ( taeniatum Group) and the sequence evidence ( Figs. 1 and 4 ), although missing A. ainictum , shows it to be the sister group of all other species of Arrhyton . The three species having high ventral scale counts and long tails ( A. dolichura , A. procerum , and A. tanyplectum ), were placed together in the dolichura Group, also supported by DNA evidence ( Fig. 1 ). The remaining species, with lower ventral counts and relatively short tails, were placed in a separate group, the vittatum Group, though this is resolved (without maximal support) as paraphyletic in our phylogeny.