40. THAMNOPHIS 789 



eee. Dorsal line present over most of body, 

 ff . Dorsal line very distinct with sharply defined 

 borders not invaded by dorsal spots, little dark 

 pigmentation on gastrosteges. 



T. ordinoides elegans. p. 824. 

 ff. Dorsal line with borders invaded by dorsal 

 spots, dark pigmentation of gastrosteges often 

 present. 



g. Preocular single, dorsal spots and dark pig- 

 mentation of gastrosteges usually very promi- 

 nent. 



T. ordinoides vagrans. p. 829. 

 g*. Usually two preoculars, dorsal spots and pig- 

 mentation of gastrosteges usually less evi- 

 dent. 



T. ordinoides biscutatus. p. 834. 

 eec'. Dorsal line usually absent, or short, or in- 

 distinct. 



fff. Remnant of dorsal line usually present, pre- 

 ocular single, infralabials often more than 1 0. 

 T. ordinoides couchii. p. 838. 



fff. No dorsal line, often more than one pre- 



ocular, infralabials rarely more than 1 0. 

 gg. Lateral lines usually present, dorsal spots 

 fewer, or absent. 



T. ordinoides hammondii. p. 843. 



gg'. Lateral lines usually absent, dorsal spots 

 very numerous and prominent. 



T. angustirostris. p. 855. 



b*. Lateral stripe anteriorly upon scales of the third row 

 only, light postoral crescents present. 



T. marcianus. p. 849. 

 a*. Lateral light stripe anteriorly involving the scales of 



the fourth row. 



T. megalops. p. 852. 



