13. Cranial crests present 14. 

 No cranial crests or with very obscure indications of them 23. 



14. Lower edge of parotoid gland below the middle of the tympanum, usually 



level with the lower margin or below 15. 



Lower edge of parotoid gland above the middle of the tympanum 17. 



15. Parotoid glands enormous, triangular, about as large as the sides of the 



head; color usually brownish; the largest native toad, getting to be 

 eight inches long; southern Texas 



Bufo marinus (Linn.) Giant Toad 

 Parotoid glands smaller, oval 16. 



16. With conspicuous glands on tibia and femur; cranial crests curved around 



behind the eyes posteriorly; color greenish; California 



Bufo alvarius Girard Colorado River Toad 

 No such glands; cranial crests straight, inconspicuous; color grayish to 

 brownish, usually with a light mid-dorsal stripe; the smallest native 

 toad, getting to be one and oncquarter inches long; N. C. to Florida 

 and Louisiana 



Bufo quercicus Holbrook Oak Toad 



17. With a transverse ridge joining the posterior ends of the parallel cranial 



crests and extending obliquely sideways scarcely behind the eyes, ending 

 abruptly; usually with a dark band, bordered with light below, along 

 each side; North Dakota 



Bufo hemiophrys Cope Northern Toad 

 No transverse ridge joining the cranial crests posteriorly; color various 18. 



18. With widely divergent cranial crests joining anteriorly in a conspicuous 



boss or knobby elevation; body skin enclosing femur; Minn, to Calif. 

 Bufo cognatus Say Plains Toad 

 Cranial crests not so; body skin enclosing half or less of femur 19. 



19. Cranial crests almost as far apart as the parotoid glands; parotoid glands 



triangular; both sole tubercles inconspicuous; with an oblique light 

 band along each side; Louisiana to New Mexico 

 Bufo valliceps Wiegmann Mexican Toad 

 Cranial crests much nearer together; parotoid glands oval; inner sole tU' 

 bercle enlarged and with a narrow cutting edge; color various 20. 



20. Cranial crests elevated posteriorly and swollen into knobs; parotoid glands 



short-oval; N. C. to Florida and Louisiana 



Bufo terrestris (Bonnaterre) Southern Toad 

 (Bufo lentiginosus lentiginosus of Cope) 

 Cranial crests not so; parotoid glands long-oval 21. 



21. With a short ridge or crest passing backwards from the postorbital crest 



(transverse ridge behind the eye) to the parotoid gland; parotoid glands 

 usually nearer together than the length of one gland; belly often more 

 or less spotted; eastern U. S. to Oklahoma 



Bufo americanus Holbrook American Toad 

 No ridge or crest so situated; parotoid glands usually farther apart; ventral 

 spots, if present, usually restricted to a small area on the breast 22. 



344 



