84 



S.B. HEDGES 



Table 1 Species, species groups, and distributions of snakes of the genus 

 Tropidophis. 



Species 



Species Group 



Distribution 



T. battersbyi Laurent 



taczanowskyi 



South America 



T. bucculentiis Cope 



melanurus 



Navassa Island 



T. canus Cope 



melanurus 



Bahamas 



T. caymanensis Battersby 



melanurus 



Grand Cayman 



T. celiae Hedges, Estrada, and Diaz 



melanurus 



Cuba 



T. curtus Garman 



melanurus 



Bahamas 



T. feicki Schwartz 



maculatus 



Cuba 



T. fuscus Hedges and Garrido 



pardalis 



Cuba 



T. galacelidus Schwartz and Garrido 



pardalis 



Cuba 



T. greenwayi Barbour and Shreve 



haetianus 



Turks and Caicos 



T. haetianus Cope 



haetianus 



Hispaniola 



T. hardyi Schwartz and Garrido 



pardalis 



Cuba 



T. hendersoni Hedges and Garrido 



pardalis 



Cuba 



T. jamaicensis Stull 



jamaicensis 



Jamaica 



T. maculatus Bibron 



maculatus 



Cuba 



T. melanurus Schlegel 



melanurus 



Cuba 



T. morenoi Hedges, Garrido, and Diaz 



maculatus 



Cuba 



T. nigriventris Bailey 



pardalis 



Cuba 



T. pardalis Gundlach 



pardalis 



Cuba 



T. parked Grant 



melanurus 



Little Cayman 



T. paucisquamis Miiller 



taczanowskyi 



South America 



T. pilsbryi Bailey 



pardalis 



Cuba 



T. schwartzi Thomas 



melanurus 



Cayman Brae 



T. semicinctus Gundlach and Peters 



maculatus 



Cuba 



T. spiritus Hedges and Garrido 



pardalis 



Cuba 



T. stejnegeri Grant 



jamaicensis 



Jamaica 



T. stullae Grant 



jamaicensis 



Jamaica 



T. taczanowskyi Steindachner 



taczanowskyi 



South America 



T. wrighti Stull 



pardalis 



Cuba 



Havana). In nearly all cases, museum numbers and localities of 

 those specimens are listed in the publications and therefore are not 

 repeated here. 



In some cases, summary data presented in the tables of Schwartz 

 and Marsh (1960) do not agree with those in the raw data sheets or 

 with data mentioned in the text of Schwartz and Marsh, presumably 

 because of typographical errors in their tables. Some of the data 

 presented later in Schwartz and Henderson (1991), such as the 

 ventral range of T. canus and caudal range of T. maculatus, appear to 

 be derived from those typographical errors. Although these errors 

 are minor, the summary data presented in this paper were taken 

 directly from Schwartz's raw data sheets, to avoid any confusion, 

 and supplemented with additional data. Also, some characters were 

 not scored by Schwartz in some species (e.g., parietal contact in T. 

 feicki, T. melanurus, T. semicinctus, etc) or at all (e.g., ratios of eye 

 length to head width and head width to neck width, and aspects of 

 colour pattern). In those cases, specimens at hand were examined to 

 fill in the gaps. I have examined preserved material of most taxa, and 

 have observed and collected 12 of the species: T. canus, T. feicki, T. 

 fuscus, T. greenwayi, T. haetianus, T. maculatus, T. melanurus, T. 

 pardalis, T. pilsbryi, T. stejnegeri, T. stullae, and T. wrighti. 



Because this is not a comprehensive revision, there was no 

 attempt to survey all collections for holdings of Tropidophis or to 

 examine all available material. It is anticipated that such an under- 

 taking will be attempted in the future. 



RESULTS AND DISCUSSION 



The conclusion of this taxonomic update is the recognition of 29 

 species of Tropidophis (Table 1). This is an increase of about six 

 species over the number recognised earlier this year (Hedges & 



Garrido, 2002). The difference involves the elevation of some taxa 

 previously considered as subspecies. Below, I discuss the utility of 

 different characters used, my reasoning in determining species 

 boundaries, and the taxonomic issues involved in each geographic 

 area. The phylogeny and biogeography of species in this genus, 

 using DNA sequence data, is discussed elsewhere (S. B. Hedges. S. 

 C. Duncan, A. K. Pepperney, in preparation). The species group 

 status (Table 1 ) is based on that work, but otherwise the focus of this 

 current assessment is the definition of species boundaries, not 

 phylogenetic relationships. 



Characters 



Variation in 20 characters among the 29 species of Tropidophis is 

 shown in Tables 2-4. They are grouped into those involving propor- 

 tions (Table 2), scalation (Table 3), and pattern and coloration (Table 

 4). In general, sexual dimorphism in Tropidophis is not pronounced 

 and therefore data from both sexes can be combined, with the 

 exception of body size, which shows slight differences. Characters 

 that I have found to be of limited value have been eliminated. These 

 include four that are commonly scored in snake systematics: upper 

 and lower labials and the pre- and postoculars. All four are variable 

 within species and in almost all cases, not diagnostic. Upper labials 

 are usually 9-10 and lower labials usually 9-12 in all species. In T. 

 melanurus and some related species, labial counts tend to be higher, 

 although even in those cases there is often overlap. There is usually 

 one preocular and 2-3 postoculars in Tropidophis, although some 

 species occasionally have two preoculars and as many as 4 

 postoculars; however, variation in ocular scales does not appear to 

 be of taxonomic utility. Examples of exceptions, as noted by Schwartz 

 and Marsh (1960), are T. pardalis (usually 2 postoculars) and T. 

 maculatus (usually 3 postoculars), although such differences are 

 rarely diagnostic. Stull ( 1 928) considered the forking of the hemipenis 

 (bifurcate versus quadrifurcate) to be a diagnostic character but 

 Schwartz and Marsh (1960) could not identify any species or 

 specimens with a quadrifurcate condition. Also, such a character 

 would not be very useful in this group because of limited material 

 and scarcity of specimens with properly everted hemipenes. 



Schwartz scored several other characters in Tropidophis, but I 

 have also found them to be of limited value in diagnosing taxa. In the 

 case of relative tail length (Schwartz & Marsh, 1960), it is useful in 

 distinguishing T. canus from T curtus (see below) but otherwise is 

 difficult to score because of tail damage in some specimens, and 

 overlapping of ratios. The colour of the tail tip (pale versus dark) was 

 useful in distinguishing Cayman Islands Tropidophis from T. 

 melanurus (Thomas, 1963), and other trends are noticeable, but 

 differences between juveniles and adults, and intraspecific variabil- 

 ity, make it a less useful character. 



Now considering the 20 tabulated characters, maximum snout- 

 vent length (SVL) is useful because some species differ greatly in 

 body size, and most individuals encountered are adults. Two ratios 

 (Table 2) that I have found to be of utility are eye length/head width 

 (i.e., relative size of the eye) and head width/neck width (i.e., 

 distinctiveness of the head). Both ratios are larger in the arboreal 

 species T feicki, T semicinctus, and T. wrighti, and in another 

 gracile Cuban species (T. fuscus) that is possibly arboreal (Hedges & 

 Garrido, 1992). Unfortunately, both show variation within species 

 and sample sizes still are small. 



Despite the intraspecific variability in the scale characters (Table 

 3), some are useful when considered simultaneously with other 

 characters. Ventral and midbody scale row counts are perhaps the 

 most useful whereas caudal counts and posterior scale row counts 

 are the least useful. Contact of the two parietal scales can be 





