48. CROTALUS 



f. — Dorsal rhombs usually not enclosing light later- 

 al areas. 



C. atrox.— p. 914. 



r. — Dorsal rhombs usually enclosing light lateral 

 areas as pale as the ground color. Tortuga 

 Island. 



C. tortugensis.— p. 918. 



e'. — First supralabial usually divided transversely; 

 general coloration reddish, pinkish or yellowish. 

 ff. — General coloration reddish, pinkish or yellow- 

 ish; markings duller and less definite; dorsal 

 blotches not usually completely surrounded by 

 light margins; gastrosteges usually more num- 

 erous. 



C. exsul.— p. 919. 



ff. — General coloration yellowish; markings much 



brighter and more definite, less punctulate; 



dorsal blotches usually completely surrounded 



by light margins; gastrosteges usually fewer. 



C. lucasensis. — p. 925. 



d'. — Tail brownish or grayish with darker brown (rare- 

 ly in part blackish) cross-bands; light postocular 

 line, if present, reaching row of scales next above 

 supralabials at or posterior to corner of mouth, 

 if at all. 

 ee. — Intervals between dorsal dark blotches less than 

 length of blotches along midline, 

 f f f . — Dorsal blotches large, forming a single series, 

 g. — Rostral not wider than high, 

 h. — Gastrosteges average more numerous (158 

 to 189); no vertical white line across mid- 

 dle of rostral plate nor two white lines on 

 side of head. 



