114 Trans. Acad. Sci. of St. Louis. 



Dorso-dermal folds present; skin of back rough; tympanum 

 nearly as large as eye, or larger; toes webbed nearly to tips; 

 heel not reaching muzzle; dark blotches on back; size mod- 

 erate, clamitans. 



No dorso-dermal folds; tympanum usually as large as eye, or 

 larger; toes webbed to tips; usually some blotches above; size 

 large. catesbiana. 



Sides of head with a black patch. 



Head in distance from snout to vent 3. .5 times; tympanum one- 

 half the eye; skin of middle of back smooth; heel to middle of 

 orbit. cantabrigensis. 



Head in length three times; tympanum two-thirds the diam- 

 eter of eye; skin of middle of back rough; heel to muzzle or 

 more. sylvatica. 



28. Rana pipiens Schreber. Leopard Frog. Common 

 Frog. 



Rana halecina, Rana virescens, Rana virginiana, Rana aquatica, Rana 

 utricularia, Rana oxyrhynchus, Rana berlandieri. 



Description. — Head varying in relative length, being contained In 

 length of head and body from 2.5 to 3.5 times. Vomerine teeth in two 

 slightly oblique patches between the choanae. Tympanum about as 

 large as the eye. Head rather elongated. A glandular fold along the 

 upper jaw and a well-marked one on each side of back; generally a 

 pair of ridges on coccyx. Femur less than tibia; the latter more than 

 one-half length of head and body. Toes moderately webbed. 



Color. — Ground color ashy, olive or bright green above; below uni- 

 form white or yellowish. The upper surface with a number of rounded 

 or oval brown spots, and these usually bordered with yellowish. The 

 spots between the dorso-lateral folds are larger, and may be arranged 

 in two or three rows, or may be irregularly placed. Outside these 

 folds are two or three rows of smaller spots. The upper surfaces of 

 the limbs are more or less conspicuously barred or spotted. Males 

 have vocal sacs, which open by a small slit near the angle of the mouth. 

 These sacs appear to be protruded through the slits. (Hay.) 



Size. — Head and body 88 mm.; from tip of snout to axilla 33 mm. 

 Femur 48 mm.; tibia 52 mm.; tarsus and fourth toe together 70 mm. 



Habitat. — Maine to Mexico, but mostly in the eastern 

 United States. Common everywhere in Missouri. 



Habits. — The Leopard Frog is our commonest, best 

 known, and most beautiful frog. It makes its appearance 



