FAMILY VII. RANID/E.' 

 THE COMMON LEOPARD FROG 1 



Rana pipiens Shreber 3 

 IDENTIFICATION CHARACTERISTICS 



Colour: Green, grey or brown, with somewhat rapid change 

 from one colour to the other. Two irregular rows of rounded dark 

 spots between the yellowish or bronze lateral folds. Two still 

 more irregular rows of spots below the lateral folds on each side. 

 Spots usually bordered conspicuously with lighter colour. Brown 

 bands or disconnected spots on the legs. The underparts are 

 white, possibly yellowish. (See Colour Plates XI and XII.) 



Measurements: Size medium to large, i. e. male 3^ inches; 

 female larger. Body relatively slender. Head more or less 

 pointed, its length contained in whole length of frog from three 

 to three and a half times. Legs long, length to heel equal to 

 length of head and body. Ear round, about two-thirds as large 

 as eye. 



Structure: Skin relatively smooth or somewhat tubercular. 

 Line from nostril to eye prominent. Broad, flattened lateral 

 folds are conspicuous. Two (or four) more or less broken folds of 

 skin extend lengthwise along the back between the lateral folds. 

 (Fig. 217.) Webs deeply indented. Tubercles under joints of 

 toes rather prominent. Inner sole tubercle small ; no outer tuber- 

 cle. (Fig. 198.) 



1 Refer to pp. 8, n and 48. 



a The Leopard Frog is called "Spring Frog" in Florida and "Grass Frog" in New York. 



8 Rana pipiens Shreber is Rana virescens Kalm (Cope) and Rana virescens brachycephala 

 Cope ("Batrachia of North America "). It has not been possible, in living material obtained from 

 New England, New York, Michigan, Minnesota, Wisconsin, Colorado, Texas, and Arizona, to make 

 a distinction into these subspecies. The variation of the frogs is remarkable, but no fundamental 

 characteristic (such as proportionate length of head and body, leg measurement, etc.) remains stable 

 when a large series of frogs from adjoining districts are examined. Eastern specimens are likely to be 

 green or brown, Southern and Western specimens are more often grey. Eastern frogs, especially 

 those that frequent the salt marshes of the coast, are more smooth-skinned and slender, and on the 

 whole, more delicately moulded, while Southern and Western specimens are much more robust in 

 build, have a rougher skin, and attain a larger size. The material is very confusing. With a smaller 

 series, the subspecies might have been granted. With a still more complete series, it is possible that 

 two or three intergrading varieties of the species Pipiens could be recognized. Much systematic 

 study of such a series of frogs, combined with knowledge of their habits and life histories, could 

 alone produce any definite conclusion in the matter. 



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