Key 



Head short. 

 Chorophilus n. jeriarum. (See Fig. 185, also pp. 157 and 160.) 



(6) Leg shorter (length to heel equals length of frog forward 

 to eye) ; head long. Middle and Western United States, 

 east of the Rocky Mountains. 



Chorophilus n. triseriatus. (See pp. 157 and 160.) 



(c) Leg short (length to heel equals length forward to shoulder 

 or ear) ; head long. Northern North America. 

 Chorophilus n. septentrionalis. (See pp. 157 and 160.) 



b. Posterior surface of femur spotted; a light blotch above the dark edge 

 of the jaw; leg short (length to heel equals length forward to 

 ear or eye); size i^ inches. Southern United States. 



Chorophilus ornatus. (See p. 161.) 



FIFTH KEY. Species of Engystomatid^ {Narrow-mouthed Toads) 

 I. Two large sole tubercles; toes with short webs; muzzle short in front of 

 eyes (less than twice the longitudinal diameter of the eye); size i^ 

 inches. Texas. 



Hypopachus cuneus. (See Colour Plate II, also p. 169.) 



II. One small sole tubercle; no webs; muzzle in front of eyes longer (more 

 than twice the longitudinal diameter of the eye). 



A. Skin very smooth; form slender; head to shoulder one-tlurd total length 



size I inch. Texas. 



Engystoma texense. (See Fig. 193, also p. 168.) 



B. Skin finely tubercular; form stout; head to shoulder one-fourth total 



length; size if inches. Southern United States. 



Engystoma carolinense. (See Colour Plate II, also p. 166.) 



SIXTH KEY. Species of Ranid^ (Frogs) 



I. Lateral folds present. 



A. Skin with longitudinal folds between the lateral folds; definitely outlined 

 spots on the back and sides; leg to heel equals or exceeds total 

 length. 



1. Spots squarish; undersurfaces of legs bright orange-yellow. Eastern 



North America. 



Rana palustris. (See Colour Plate XIII, also p. 188.) 



2. Spots rounded. 



a. Head long (two and a half times in total length) ; circular white sjJOt 

 at centre of ear; spots on back not outlined with light. Southern 

 States. 



Rana sphenocephala. (See Colour Plate XII, also p. 186.) 

 48 



