10 FROGS. 



parts are white, with some marbhng ; in the male the throat is yellow. 

 This species reaches 3 J to 4 inches or more in length and extends in 

 range from the Gulf of Mexico to Hudson Bay, occurring in practi- 

 cally all of eastern North America. 



Bullfrog. — The bullfrog (PI. I) is much larger than the green frog, 

 and the two are often confused. The bullfrog has no ridges down 

 either side of its back. On its upper parts it may vary from yel- 

 lowish green to a dark brown, while its under parts are yellowish 

 white, with some mottlings. In size it may reacm 8 inches, and its 

 range is from eastern North America to the Kockies. 



The Southern Bullfrog. —The southern bullfrog is quite similar 

 to the common bullfrog and varies from brownish olive to bone brown 

 or blackish brown above, with some prominent, scattered black spots. 

 The under parts often have a network of black or brown and yellow, 

 one of the most striking ventral colorations of any North American 

 frog. This species has a more pointed snout than the bullfrog, pos- 

 sesses a narrower head (measured at the eardrums), and has all the 

 hind toes except the fourth proportionally longer than the same toes 

 of the bullfrog. Of this form, the author has taken no specimens over 

 5 or 6 inches in length, while the extreme for the bullfrog may be much 

 more. The known range of the southern bullfrog is in the extreme 

 southeastern United States. 



Leopard Frog. — ^The leopard frog or meadow frog (PI. Ill, fig. 1), 

 the most widespread and most common form of North America, has 

 all the under parts white or whitish. On either side of the back is a 

 prominent fold, which is narrower and higher than in the pickerel frog. 

 Between these two main folds sometimes there are other smaller folds. 

 The spots between the two folds are irregular in outline and in posi- 

 tion, are not necessarily opposite, and occupy less space than the 

 background color, whicn varies from bronze to green. The spots 

 below the lateral fold are less regularly placed and never so large as 

 in the pickerel frog. The leopard frog reaches a length of 3 ^ to 4 

 inches and is found from the Sierra Nevada Mountains eastward and 

 from the extreme north to Mexico. 



The Southern Leopard Frog. — The southern leopard frog is 

 very similar to the common leopard frog and varies from it in a very 

 few characters. It usually has a distinct white sf)ot in the middle of 

 the eardrum, unlike the leopard frog, in which it is generally absent. 

 Then, the head of the southern form is contained 2.5 times, or less 

 than 3 times, in the length of the head and body combined, while 

 the common form has it 3 to 3 .5 times. Furthermore, in the southern 

 species the snout is acuminate or pointed and is contained about 1.5 

 times in the head, while in the other form the snout is less pointed and 

 is contained 2 or more times in the head. This species may reach 

 the size of a common meadow frog and occurs in the southern States. 



Pickerel Frog.— The pickerel frog (PI. Ill, fig. 2), in life has the 

 under parts of the legs and belly orange yellow. On either side of 

 the back is a broad, low fold of skin. Between these folds there are 

 two regular, more or less opposite, rows of dark, squarish spots, 

 which occupy far more of the back than the light-brown, ground 

 color. Below each back fold the spots are larger and more regular 

 than in the leopard frog. The pickerel frog reaches a length of 3 to 

 3^ inches and is found from the central plains to the Atlantic sea- 

 board and from the Gulf of Mexico to Hudson Bay. 



