Giant Toad. Colorado River Toad. Girard's 



Toad. Colorado Toad. 



Plate IX. i, 2, 3, 4. Fe- 

 males (xj). 



Bufo alvarius Girard. 



Range: Southern Arizona 

 and southern California into 

 Mexico. 



Habitat: Semi-aquatic. 

 General locality of large per- 

 manent streams or the irri- 

 gated portions of our south- 

 western desert regions. 



Size: Adults, 3 1/4-6 3/5 

 inches. (Males, 80-156 mm. 

 Females, 87-165 mm.). 



General appearance: This is 

 a very large grayish or brown- 

 ish green toad with smooth 

 leathery skin and a few 

 scattered small rounded 

 warts. The under parts are 

 light. The head is broad and 

 flat, marked by low broad 

 crescent shaped crests curv- 

 ing around the rear of the 

 eye. These are like fleshy 

 folds. The canthus rostralis is 

 marked by a ridge which 

 turns down in front of the 

 eye as a preorbital. One to 

 four white warts are present 

 back of the angle of the 

 mouth. The parotoids are 

 large, subreniform in shape 

 spreading downward at the 

 shoulder. There is a large 

 glandular wart on the femur 

 and a long one or several 

 shorter ones on the tibia. 

 These glands are the con- 

 spicuous mark of this toad 

 and appear early, being pres- 

 ent in a 1 3/4 inches (44 mm.) 

 individual. 



46 



