21 



11. Middorsal dark stripe relatively broad, occupying as little as all of middorsal scale row 



or as much as middorsal row and adjacent halves of paravertebral rows; head pattern 

 of spatulate dark anterior extension of middorsal dark stripe flanked by narrow 

 longitudinal pale markings and short pale middorsally-interrupted nuchal collar set off 



markedly from ground color of dorsolateral field T. deppei 



Middorsal dark stripe relatively narrow, occupying middle of middorsal row, connected 

 to dark markings along medial edges of scales of paravertebral row; head pattern of 

 brown head cap with two comiform anterior extensions, followed by two pale nuchal 

 spots, which grade posteriorly into dorsal ground color T. insulamontana 



12. Length of venter with narrow irregular median dark line T. miyatai 



No markings on medial portion of venter 13 



13. Dorsum of head with extensive pale pigment on dark background, including large pale 



marking on snout, confluent with pale markings on supraoculars and anterolateral 



portion of parietals, latter in contact with postocular pale spot T. andinista 



Pale markings on head confined to markings on snout (if present) and pale pre- and 

 postocular spots 1 4 



14. Dorsal pattern multilineate, consisting of many dark stripes on a pale ground color, 



including dark stripes on dorsolateral field T. equatoriana 



Color pattern not as above, no dark striping on dorsolateral field 1 5 



15. Dorsal ground color tan with a narrow, diffuse, poorly-defined middorsal stripe and no 



pale lateral stripe; pale nuchal band complete or medially divided, head cap same 



color as dark nape band T. capistrata (part) 



Dorsal pattern not as above 16 



16. Head pattern of brown head cap with pair of small, indistinct nuchal spots, largely 



confined to scales posterior to parietals, and no dark lateral extension of head cap 

 between postocular pale spots and pale pigment on lateral gulars; subcaudals 



relatively low, 36-44 T. lempira 



Color pattern variable, but head pattern of cream to dark brown head cap with pale 

 nuchal collar complete, divided medially, divided medially and laterally, or reduced to 

 two small spots centered on parietals, and dark lateral extension of head cap between 

 postocular pale spot and pale pigment on lateral gulars usually present (except in 

 some specimens from Costa Rica and western Panama), subcaudals variable, but 

 relatively high, 4 1 -92 T. melanocephala (part) 



