Ranidae 



pecting insect, bird, or batrachian. It disappears so quickly 

 at the approach of danger, that not only is it seldom seen, but, 

 to be captured, must in all cases be dug out of the burrow. 



This frog seems especially fond of toads as an article of diet. 

 It ejects the poison from the mouth as soon as it has swallowed 

 the toad. A toad of surprisingly large size can be managed, 

 owing to the unusual development of the jaws and throat of 

 this species. If the toad is too large to be all swallowed at once, 

 so that the poison can be sent out through the mouth almost 

 immediately, the frog gives up the attempt and disgorges the 

 toad after about fifteen minutes. This time, however, is sufficient 

 to allow some action of the poison to take place, and the frog 

 shows many signs of discomfort. It has convulsive movements 

 of the muscles, it leaps blindly upward, and finally, lowering 

 the head and opening the cavernous mouth, uses the hands in 

 frantic efforts to remove the irritation from there. During 

 several weeks of captivity, Rana asopus fed almost wholly upon 

 toads, of species lentiginosus, woodhousei, and jowleri. This 

 habit of eating toads may be duplicated in the case of Rana 

 catesbiana. At least this frog has been found dead witn full- 

 grown specimens of Bufo jowleri partially swallowed. 



RANA ONCA, COPE ' 



IDENTIFICATION CHARACTERISTICS 



Colour: Brown posteriorly; lighter anteriorly, often bright 

 metallic green, especially on sides of head under the eyes and 

 below the canthus rostralis. Iris golden. Ear bronze. Lateral 

 folds light yellowish brown. Three or more irregular rows of 

 spots between the lateral folds, and many spots placed irregu- 

 larly below the folds. Spots light edged or not. Legs light 

 brown, spotted with dark, even on the feet. Underparts white, 

 yellow posteriorly. (See Colour Plate. II.) 



Measurements: Size medium, i. e. length 2 to 3 inches. 

 Leg short ; length of leg to heel equalling length of body forward 

 to eye. Tibia but slightly longer than femur. 



i Rana jisheri Stejneger. Annotated List of Reptiles and Batrachians Collected by the Desert 

 Valley Expedition in 1891. Leonhard Stejneger. North Amer. Fauna, No. 7. 1893. 

 Also Rana draytoni onca Cope. Cope's Batrachia of North. America. 



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